xfs: make XFS_TRANS_LOWMODE match the other XFS_TRANS_ definitions

Commit bb7b1c9c ("xfs: tag transactions that contain intent done
items") switched the XFS_TRANS_ definitions to be bit based, and using
comments above the definitions.  As XFS_TRANS_LOWMODE was last and has
a big fat comment it was missed.  Switch it to the same style.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

fs/xfs/libxfs/xfs_shared.h

@@ -124,7 +124,6 @@ void	xfs_log_get_max_trans_res(struct xfs_mount *mp,
 #define XFS_TRANS_RES_FDBLKS		(1u << 6)
 /* Transaction contains an intent done log item */
 #define XFS_TRANS_HAS_INTENT_DONE	(1u << 7)
-
 /*
  * LOWMODE is used by the allocator to activate the lowspace algorithm - when
  * free space is running low the extent allocator may choose to allocate an
@@ -136,7 +135,7 @@ void	xfs_log_get_max_trans_res(struct xfs_mount *mp,
  * for free space from AG 0. If the correct transaction reservations have been
  * made then this algorithm will eventually find all the space it needs.
  */
-#define XFS_TRANS_LOWMODE	0x100	/* allocate in low space mode */
+#define XFS_TRANS_LOWMODE		(1u << 8)
 
 /*
  * Field values for xfs_trans_mod_sb.