btrfs: warn if leaking delayed_nodes in btrfs_put_root()

Add a warning for leaked delayed_nodes when putting a root. We currently
do this for inodes, but not delayed_nodes.

Signed-off-by: Leo Martins <loemra.dev@gmail.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
[ Remove the changelog from the commit message. ]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Author: loemraw

fs/btrfs/disk-io.c

@@ -1835,6 +1835,8 @@ void btrfs_put_root(struct btrfs_root *root)
 	if (refcount_dec_and_test(&root->refs)) {
 		if (WARN_ON(!xa_empty(&root->inodes)))
 			xa_destroy(&root->inodes);
+		if (WARN_ON(!xa_empty(&root->delayed_nodes)))
+			xa_destroy(&root->delayed_nodes);
 		WARN_ON(test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state));
 		if (root->anon_dev)
 			free_anon_bdev(root->anon_dev);