xfs: use ->t_firstblock in xfs_bmapi_remap()

Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

fs/xfs/libxfs/xfs_bmap.c

@@ -4501,7 +4501,6 @@ xfs_bmapi_remap(
 	struct xfs_mount	*mp = ip->i_mount;
 	struct xfs_ifork	*ifp;
 	struct xfs_btree_cur	*cur = NULL;
-	xfs_fsblock_t		firstblock = NULLFSBLOCK;
 	struct xfs_bmbt_irec	got;
 	struct xfs_iext_cursor	icur;
 	int			whichfork = xfs_bmapi_whichfork(flags);
@@ -4544,7 +4543,7 @@ xfs_bmapi_remap(
 
 	if (ifp->if_flags & XFS_IFBROOT) {
 		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
-		cur->bc_private.b.firstblock = firstblock;
+		cur->bc_private.b.firstblock = tp->t_firstblock;
 		cur->bc_private.b.flags = 0;
 	}
 
@@ -4557,7 +4556,7 @@ xfs_bmapi_remap(
 		got.br_state = XFS_EXT_NORM;
 
 	error = xfs_bmap_add_extent_hole_real(tp, ip, whichfork, &icur,
-			&cur, &got, &firstblock, &logflags, flags);
+			&cur, &got, &tp->t_firstblock, &logflags, flags);
 	if (error)
 		goto error0;