Merge pull request #4385 from liuan1986/master

if error is not NULL,Maybe return error would be better.

cmd/ks-apiserver/app/server.go

@@ -97,7 +97,7 @@ func Run(s *options.ServerRunOptions, ctx context.Context) error {
 
 	err = apiserver.PrepareRun(ctx.Done())
 	if err != nil {
-		return nil
+		return err
 	}
 
 	return apiserver.Run(ctx)