Qt4: fix a crash (kind of a 'use after free' error).

(cherry picked from commit 13c520d1c893ebc8420804d1c7b42c1e8fbab9b8)
Signed-off-by: Rémi Duraffort <ivoire@videolan.org>

modules/gui/qt4/menus.cpp

@@ -439,9 +439,9 @@ QMenu *QVLCMenu::ViewMenu( intf_thread_t *p_intf, QMenu *current, MainInterface
         foreach( QAction *a, actions )
         {
             QMenu *m = a->menu();
-            if( m && m->parent() == menu ) delete m;
             if( a->parent() == menu ) delete a;
             else menu->removeAction( a );
+            if( m && m->parent() == menu ) delete m;
         }
     }