reduce nesting

pkg/volume/flexvolume/probe.go

@@ -176,11 +176,9 @@ func (prober *flexVolumeProber) updateProbeNeeded() {
 // on its parent directory.
 func (prober *flexVolumeProber) addWatchRecursive(filename string) error {
 	addWatch := func(path string, info os.FileInfo, err error) error {
-		if err == nil {
-			if info.IsDir() {
-				if err := prober.watcher.AddWatch(path); err != nil {
-					glog.Errorf("Error recursively adding watch: %v", err)
-				}
+		if err == nil && info.IsDir() {
+			if err := prober.watcher.AddWatch(path); err != nil {
+				glog.Errorf("Error recursively adding watch: %v", err)
 			}
 		}
 		return nil