(vc-menu-map-filter): Use vc-call and reindent.

lisp/vc-hooks.el

@@ -964,14 +964,14 @@ Used in `find-file-not-found-functions'."
   (if (and (symbolp orig-binding) (fboundp orig-binding))
       (setq orig-binding (indirect-function orig-binding)))
   (let ((ext-binding
-   (if vc-mode (vc-call-backend (vc-backend buffer-file-name) 'extra-menu))))
+         (if vc-mode (vc-call extra-menu buffer-file-name))))
     ;; Give the VC backend a chance to add menu entries
     ;; specific for that backend.
     (if (null ext-binding)
-    orig-binding
+        orig-binding
       (append orig-binding
 	      '((ext-menu-separator "---"))
-	            ext-binding))))
+              ext-binding))))
 
 (defun vc-default-extra-menu (backend)
   nil)