xfs: remove put_value from attr ->put_listent context

The put_value context member is never set; remove it
and the conditional test in xfs_attr3_leaf_list_int().

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>