[mutter] Fix crash when right-clicking on window frame

[Owen Taylor <otaylor src gnome org>]

commit f8dd4c160b86055c4857b2229193c2bc8b45bad0
Author: Edward Sheldrake <ejs1920 yahoo co uk>
Date:   Tue Apr 6 11:46:38 2010 +0200

    Fix crash when right-clicking on window frame
    
    This is a regression added in 333446ab.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=614592

 src/core/core.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/core/core.c b/src/core/core.c
index 3fd4974..6fd2edd 100644
--- a/src/core/core.c
+++ b/src/core/core.c
@@ -527,7 +527,7 @@ meta_core_get_menu_accelerator (MetaMenuOp           menu_op,
   switch (menu_op)
     {
     case META_MENU_OP_NONE:
-      name = "none";
+      /* No keybinding for this one */
       break;
     case META_MENU_OP_DELETE:
       name = "close";