Merge pull request #59728 from wgliang/master.append

Automatic merge from submit-queue (batch tested with PRs 59740, 59728, 60080, 60086, 58714). 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>.

more concise to merge the slice

**What this PR does / why we need it**:
more concise to merge the slice

**Special notes for your reviewer**:

pkg/controller/service/service_controller_test.go

@@ -247,9 +247,8 @@ func TestUpdateNodesInExternalLoadBalancer(t *testing.T) {
 		controller, cloud, _ := newController()
 
 		var services []*v1.Service
-		for _, service := range item.services {
-			services = append(services, service)
-		}
+		services = append(services, item.services...)
+
 		if err := controller.updateLoadBalancerHosts(services, nodes); err != nil {
 			t.Errorf("unexpected error: %v", err)
 		}