#220233 follow-up by Berdir: Fix typo.

modules/node/node.module

@@ -689,7 +689,7 @@ function node_type_update_nodes($old_type, $type) {
  *
  */
 function _node_types_build() {
-  $_node_types = drupal_static(__FUNCTION__);
+  $_node_types = &drupal_static(__FUNCTION__);
   if (is_object($_node_types)) {
     return $_node_types;
   }