Fixed spelling of 'menuItem' as part of bug 101750, r=brade, sr=kin

editor/ui/composer/content/editor.js

@@ -1710,7 +1710,7 @@ function InitListMenu()
 
   // Set "radio" check on one item, but...
   var menuItem = document.getElementById("menu_"+IDSuffix);
-  if (!menuitem)
+  if (!menuItem)
     return;
 
   menuItem.setAttribute("checked", "true");