xfs: remove unused values from xfs_exntst_t

We only ever use the normal and unwritten states.  And the actual
ondisk format (this enum isn't despite being in xfs_format.h) only
has space for the unwritten bit anyway.
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_format.h

@@ -1588,7 +1588,6 @@ typedef enum {
  */
 typedef enum {
 	XFS_EXT_NORM, XFS_EXT_UNWRITTEN,
-	XFS_EXT_DMAPI_OFFLINE, XFS_EXT_INVALID
 } xfs_exntst_t;
 
 /*