Merge pull request #45192 from cehoffman/azure_deadlock

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Prevent deadlock on azure zone fetch in presence of failure

**What this PR does / why we need it**:

This fixes a bug in the Zone get function for the Azure cloud provider.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #

**Special notes for your reviewer**:

**Release note**:

```release-note
Fix deadlock in azure cloud provider zone fetching
```

pkg/cloudprovider/providers/azure/azure_zones.go

@@ -44,6 +44,7 @@ type instanceInfo struct {
 // GetZone returns the Zone containing the current failure zone and locality region that the program is running in
 func (az *Cloud) GetZone() (cloudprovider.Zone, error) {
 	faultMutex.Lock()
+	defer faultMutex.Unlock()
 	if faultDomain == nil {
 		var err error
 		faultDomain, err = fetchFaultDomain()
@@ -55,7 +56,6 @@ func (az *Cloud) GetZone() (cloudprovider.Zone, error) {
 		FailureDomain: *faultDomain,
 		Region:        az.Location,
 	}
-	faultMutex.Unlock()
 	return zone, nil
 }