xfs: log proper length of superblock

xfs_trans_log_buf takes first byte, last byte as args.  In this
case, it should be from 0 to sizeof() - 1.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

fs/xfs/libxfs/xfs_sb.c

@@ -928,7 +928,7 @@ xfs_log_sb(
 
 	xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb);
 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
-	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb));
+	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb) - 1);
 }
 
 /*