/* destroy_done_tree - destroy the done tree. @done_tree: done tree to destroy  */
static void destroy_done_tree(struct rb_root *done_tree)
/* destroy_done_tree - destroy the done tree. @done_tree: done tree to destroy  */
static void destroy_done_tree(struct rb_root *done_tree)
{
	struct done_ref *dr, *n;
	rbtree_postorder_for_each_entry_safe(dr, n, done_tree, rb)
		kfree(dr);
}