Fix VMSS cache content

Using reference to a loop iterator variable is common mistake because it
takes different values in each loop iteration.

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

@@ -73,7 +73,8 @@ func (ss *scaleSet) newVMSSCache() (*azcache.TimedCache, error) {
 				return nil, rerr.Error()
 			}
 
-			for _, scaleSet := range allScaleSets {
+			for i := range allScaleSets {
+				scaleSet := allScaleSets[i]
 				if scaleSet.Name == nil || *scaleSet.Name == "" {
 					klog.Warning("failed to get the name of VMSS")
 					continue