xfs: unlock inode when xfs_ioctl_setattr_get_trans can't get transaction

We passed an inode into xfs_ioctl_setattr_get_trans with join_flags
indicating which locks are held on that inode.  If we can't allocate a
transaction then we need to unlock the inode before we bail out, like
all the other error paths do.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

fs/xfs/xfs_ioctl.c

@@ -1153,7 +1153,7 @@ xfs_ioctl_setattr_get_trans(
 
 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
 	if (error)
-		return ERR_PTR(error);
+		goto out_unlock;
 
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
 	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL | join_flags);