Merge pull request kubernetes#84138 from nilo19/qi-fix-missing-zone-master

Return an error when zone info is not found.

Author: k8s-ci-robot

staging/src/k8s.io/legacy-cloud-providers/azure/azure_vmss.go

@@ -315,6 +315,11 @@ func (ss *scaleSet) GetZoneByNodeName(name string) (cloudprovider.Zone, error) {
 	} else if vm.InstanceView != nil && vm.InstanceView.PlatformFaultDomain != nil {
 		// Availability zone is not used for the node, falling back to fault domain.
 		failureDomain = strconv.Itoa(int(*vm.InstanceView.PlatformFaultDomain))
+	} else {
+		err = fmt.Errorf("failed to get zone info")
+		klog.Errorf("GetZoneByNodeName: got unexpected error %v", err)
+		ss.deleteCacheForNode(name)
+		return cloudprovider.Zone{}, err
 	}
 
 	return cloudprovider.Zone{