ospfd: Remove another odd flooding hack in opaque LSA code

ospfd: Remove another odd flooding hack in opaque LSA code

* ospf_opaque.c: (ospf_opaque_adjust_lsreq) Odd hack to general OSPF
  database exchange but made to act only on opaque LSAs. It's either covering
  up bugs in the flooding code or its wrong. If it's covering up bugs, those
  would affect all LSAs and should be fixed at a lower layer in ospfd, indeed
  perhaps those bugs are long fixed anyway (?). Alternatively, it's just plain
  wrong. Nuke.
  (ospf_opaque_exclude_lsa_from_lsreq) helper to above, nuke.
* ospf_packet.c: Nuke call to ospf_opaque_adjust_lsreq.

Tested-by: olivier.dugeon@orange.com