remove todo comment

addresses RIOT-OS#1041 (comment)

Author: LudwigKnuepfer

core/include/queue.h

@@ -87,10 +87,6 @@ void queue_priority_add(queue_node_t *root, queue_node_t *new_obj);
  * @param[in,out]   root    the queue's root
  * @param[in]       new_obj the object to prepend
  * @param[in]       cmp     a comparator function used to determine the priority
- *
- * @todo clean up: make queue_priority_add use queue_priority_add_generic, and
- * adjust queue_node_t accordingly.
- * Alternatively remove this function which is unused at the moment anyways.
  */
 void queue_priority_add_generic(queue_node_t *root, queue_node_t *new_obj, int(*cmp)(queue_node_t *, queue_node_t *)) ;