xfs: remove unused XFS_MOUNT_ILOCK/XFS_MOUNT_IUNLOCK

These aren't only unused but also reference a lock that doesn't exist anymore.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>

fs/xfs/xfs_mount.h

@@ -500,9 +500,6 @@ typedef struct xfs_mod_sb {
 	int64_t		msb_delta;	/* Change to make to specified field */
 } xfs_mod_sb_t;
 
-#define	XFS_MOUNT_ILOCK(mp)	mutex_lock(&((mp)->m_ilock))
-#define	XFS_MOUNT_IUNLOCK(mp)	mutex_unlock(&((mp)->m_ilock))
-
 extern int	xfs_log_sbcount(xfs_mount_t *, uint);
 extern int	xfs_mountfs(xfs_mount_t *mp);
 extern void	xfs_mountfs_check_barriers(xfs_mount_t *mp);