Print conflict error in warning level message

To better understand the failure of resource update, use the warn level message instead.

Longhorn 7106

Signed-off-by: Derek Su <derek.su@suse.com>
(cherry picked from commit 463dd8e)

controller/utils.go

@@ -14,7 +14,7 @@ func handleReconcileErrorLogging(logger logrus.FieldLogger, err error, mesg stri
 	}
 
 	if apierrors.IsConflict(err) {
-		logger.WithError(err).Debug(mesg)
+		logger.WithError(err).Warn(mesg)
 	} else {
 		logger.WithError(err).Error(mesg)
 	}