xfs: collapse cases in xfs_attr3_leaf_list_int

Consolidate the 2 calls to ->put_listent in
xfs_attr3_leaf_list_int(), by setting up name, namelen, and
valuelen for the local vs remote cases, then call ->put_listent
and do the error handling all in one spot.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>