Merge pull request #66051 from jiaxuanzhou/imageGC

Automatic merge from submit-queue (batch tested with PRs 66051, 66049). 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>.

Fix:Image garbage collection is always disabled in kubelet in 1.11 

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

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes  #66046


**Special notes for your reviewer**:
@yujuhong @derekwaynecarr 
**Release note**:

```release-note
NONE
```

pkg/kubelet/kubelet.go

@@ -1238,12 +1238,10 @@ func (kl *Kubelet) StartGarbageCollection() {
 		}
 	}, ContainerGCPeriod, wait.NeverStop)
 
-	stopChan := make(chan struct{})
-	defer close(stopChan)
 	// when the high threshold is set to 100, stub the image GC manager
 	if kl.kubeletConfiguration.ImageGCHighThresholdPercent == 100 {
 		glog.V(2).Infof("ImageGCHighThresholdPercent is set 100, Disable image GC")
-		go func() { stopChan <- struct{}{} }()
+		return
 	}
 
 	prevImageGCFailed := false
@@ -1266,7 +1264,7 @@ func (kl *Kubelet) StartGarbageCollection() {
 
 			glog.V(vLevel).Infof("Image garbage collection succeeded")
 		}
-	}, ImageGCPeriod, stopChan)
+	}, ImageGCPeriod, wait.NeverStop)
 }
 
 // initializeModules will initialize internal modules that do not require the container runtime to be up.