remove useless logs

pkg/controller/destinationrule/destinationrule_controller.go

@@ -211,9 +211,9 @@ func (v *DestinationRuleController) syncService(key string) error {
 
 	service, err := v.serviceLister.Services(namespace).Get(name)
 	if err != nil {
-		// Delete the corresponding destinationrule, as the service has been deleted.
+		// Delete the corresponding destinationrule if there is any, as the service has been deleted.
 		err = v.destinationRuleClient.NetworkingV1alpha3().DestinationRules(namespace).Delete(name, nil)
-		if !errors.IsNotFound(err) {
+		if err != nil && !errors.IsNotFound(err) {
 			log.Error(err, "delete destination rule failed", "namespace", namespace, "name", name)
 			return err
 		}

pkg/controller/virtualservice/virtualservice_controller.go

@@ -264,9 +264,7 @@ func (v *VirtualServiceController) syncService(key string) error {
 	subsets := destinationRule.Spec.Subsets
 	if len(subsets) == 0 {
 		// destination rule with no subsets, not possibly
-		err = fmt.Errorf("found destinationrule with no subsets for service %s", name)
-		log.Error(err, "found destinationrule with no subsets", "namespace", namespace, "name", appName)
-		return err
+		return nil
 	}
 
 	// fetch all strategies applied to service