ocfs2/quota: Release lock for error in ocfs2_quota_write.

ocfs2_quota_write needs to release the lock if it fails to
read quota block. So use "goto out" instead of "return err".
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

fs/ocfs2/quota_global.c

@@ -238,7 +238,7 @@ ssize_t ocfs2_quota_write(struct super_block *sb, int type,
 	}
 	if (err) {
 		mlog_errno(err);
-		return err;
+		goto out;
 	}
 	lock_buffer(bh);
 	if (new)