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 <[e-mail]>
Acked-by: Jan Kara <[e-mail]>
Signed-off-by: Joel Becker <[e-mail]>

fs/ocfs2/quota_global.c

···
 	}
 	if (err) {
 		mlog_errno(err);
-		return err;
+		goto out;
 	}
 	lock_buffer(bh);
 	if (new)