gfile: Fix g_file_peek_path() for remote locations

g_file_peek_path() doesn't work for GVfs locations on the first attempt,
because the compare-and-swap loop is broken before the return value is
set.

gio/gfile.c

@@ -568,7 +568,10 @@ file_peek_path_generic (GFile *file)
       if (g_object_replace_qdata ((GObject *) file, _file_path_quark,
                                   NULL, (gpointer) new_path,
                                   (GDestroyNotify) g_free, NULL))
-        break;
+        {
+          path = new_path;
+          break;
+        }
       else
         g_free (new_path);
     }