ext4: fix buffer leak in ext4_xattr_move_to_block() on error path

BugLink: https://bugs.launchpad.net/bugs/1810947

commit 6bdc9977 upstream.

Fixes: 3f2571c1 ("ext4: factor out xattr moving")
Fixes: 6dd4ee7c ("ext4: Expand extra_inodes space per ...")
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org # 2.6.23
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

fs/ext4/xattr.c

@@ -1552,6 +1552,8 @@ int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
 	kfree(buffer);
 	if (is)
 		brelse(is->iloc.bh);
+	if (bs)
+		brelse(bs->bh);
 	kfree(is);
 	kfree(bs);
 	brelse(bh);