xfs: fix integer truncation in xfs_bmap_remap_alloc

bno should be a xfs_fsblock_t, which is 64-bit wides instead of a
xfs_aglock_t, which truncates the value to 32 bits.
Signed-off-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

@@ -3863,7 +3863,7 @@ xfs_bmap_remap_alloc(
 {
 	struct xfs_trans	*tp = ap->tp;
 	struct xfs_mount	*mp = tp->t_mountp;
-	xfs_agblock_t		bno;
+	xfs_fsblock_t		bno;
 	struct xfs_alloc_arg	args;
 	int			error;