/* If @old was empty, it will be overwritten.  */
static void list_replace(struct list_head *old, struct list_head *new)
/* If @old was empty, it will be overwritten.  */
static void list_replace(struct list_head *old, struct list_head *new)
{
	new->next = old->next;
	new->next->prev = new;
	new->prev = old->prev;
	new->prev->next = new;
}