Merge pull request #4049 from fuweid/me-fix-flaky-testcase

cleanup the image synchronously for Usage case

image_test.go

@@ -151,7 +151,7 @@ func TestImageUsage(t *testing.T) {
 	defer client.Close()
 
 	// Cleanup
-	err = client.ImageService().Delete(ctx, imageName)
+	err = client.ImageService().Delete(ctx, imageName, images.SynchronousDelete())
 	if err != nil && !errdefs.IsNotFound(err) {
 		t.Fatal(err)
 	}