tools/magit: fix +magit/quit & default display fn

When used with magit-display-buffer-traditional, q wouldn't close the
window, just kill the buffer inside.

modules/tools/magit/autoload.el

@@ -53,9 +53,13 @@
   "Clean up magit buffers after quitting `magit-status' and refresh version
 control in buffers."
   (interactive)
-  (if (cdr (delq nil (mapcar (lambda (win) (with-selected-window win (eq major-mode 'magit-status-mode)))
-                             (window-list))))
   (quit-window)
+  (unless (cdr
+           (delq nil
+                 (mapcar (lambda (win)
+                           (with-selected-window win
+                             (eq major-mode 'magit-status-mode)))
+                         (window-list))))
     (mapc #'+magit--kill-buffer (magit-mode-get-buffers))
     (dolist (buffer (buffer-list))
       (with-current-buffer buffer