xfs: make largest supported offset less shouty

XFS_MAXIOFFSET() is just a simple macro that resolves to
mp->m_maxioffset. It doesn't need to exist, and it just makes the
code unnecessarily loud and shouty.

Make it quiet and easy to read.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index a59eea0..257f3c4 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1226,7 +1226,7 @@
 	 * then there is nothing to do.
 	 */
 	first_unmap_block = XFS_B_TO_FSB(mp, (xfs_ufsize_t)new_size);
-	last_block = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
+	last_block = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
 	if (first_unmap_block == last_block)
 		return 0;