[FIX] incorrect return value for fix_view_modes in case the view_type is tree

bzr revid: xmo@openerp.com-20110705064817-pxjafkogvc3tub4t

addons/base/controllers/main.py

@@ -325,7 +325,7 @@ def fix_view_modes(action):
         generate_views(action)
 
     if action.pop('view_type') != 'form':
-        return
+        return action
 
     action['views'] = [
         [id, mode if mode != 'tree' else 'list']