/* Initialize an urb_link to be a single element list. If the urb_link is being used as a distinguished list head the list is empty when the head is the only link in the list.  */
void urb_link_init(urb_link *ul)
/* Initialize an urb_link to be a single element list. If the urb_link is being used as a distinguished list head the list is empty when the head is the only link in the list.  */
void urb_link_init(urb_link *ul)
{
	if (ul) {
		ul->prev = ul->next = ul;
	}
}