xfs: remove logged flag from inode log item

This was used to track if the item had logged fields being flushed
to disk. We log everything in the inode these days, so this logic is
no longer needed. Remove it.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>