CA: Fix potential race/deadlock in CAPI unstructured handling

[joelsmith]

The change to add the mutex was introduced after 1.34 branched so it has never landed in a CA release. This fix should probably be cherry-picked to the CA 1.35 release branch, ideally prior to the release of 1.35.0.

What type of PR is this?

/kind bug

What this PR does / why we need it:

Since unstructuredScalableResource contains a sync.RWMutex, it should be
passed by reference so that all locks/unlocks can be performed against a
single mutex instance (and not a copy of the mutex)

Before:

$ go vet ./cloudprovider/clusterapi/
# k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi
# [k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi]
cloudprovider/clusterapi/clusterapi_unstructured.go:55:9: ID passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:59:9: MaxSize passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:63:9: MinSize passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:67:9: Kind passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:71:9: GroupVersionResource passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:84:9: Name passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:88:9: Namespace passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:92:9: ProviderIDs passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:101:9: Replicas passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:118:9: SetSize passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:169:9: UnmarkMachineForDeletion passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:183:9: MarkMachineForDeletion passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:204:9: Labels passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:230:9: Taints passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:249:9: CanScaleFromZero passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:266:9: InstanceCapacity passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:340:9: InstanceSystemInfo passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:349:9: InstanceResourceSlices passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:389:9: InstanceEphemeralDiskCapacityAnnotation passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:393:9: InstanceCPUCapacityAnnotation passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:397:9: InstanceMemoryCapacityAnnotation passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:401:9: InstanceGPUCapacityAnnotation passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:405:9: InstanceGPUTypeAnnotation passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:409:9: InstanceMaxPodsCapacityAnnotation passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:413:9: InstanceDRADriver passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:421:9: InstanceCSINode passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex
cloudprovider/clusterapi/clusterapi_unstructured.go:438:9: readInfrastructureReferenceResource passes lock by value: k8s.io/autoscaler/cluster-autoscaler/cloudprovider/clusterapi.unstructuredScalableResource contains sync.RWMutex

After:

$ go vet ./cloudprovider/clusterapi/

Which issue(s) this PR fixes:

None

Special notes for your reviewer:

Does this PR introduce a user-facing change?

NONE

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

[k8s-ci-robot]

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This pull-request has been approved by: joelsmith
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