lustre: lov: Drop unneeded set_oabufs and set_pga fields

The fields set_oabufs and set_pga fields in the lov_request_set structure
are never set, so drop them.  Drop also the corresponding test and free in
lov_finish_set.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>