fix ticker leak

Signed-off-by: rokkiter <yongen.pan@daocloud.io>

cmd/containerd-stress/cri_worker.go

@@ -117,25 +117,21 @@ func (w *criWorker) runSandbox(tctx, ctx context.Context, id string) (err error)
 	// verify it is running ?
 
 	ticker := time.NewTicker(250 * time.Millisecond)
-	quit := make(chan struct{})
 	go func() {
 		for {
 			select {
 			case <-tctx.Done():
-				close(quit)
+				ticker.Stop()
 				return
 			case <-ticker.C:
 				// do stuff
 				status, err := w.client.PodSandboxStatus(sb)
 				if err != nil && status.GetState() == runtime.PodSandboxState_SANDBOX_READY {
-					close(quit)
-					return
-				}
-			case <-quit:
 					ticker.Stop()
 					return
 				}
 			}
+		}
 	}()
 
 	return nil