ospfd: fix regression in recent commit

commit '717750433839762d23a5f8d88fe0b4d57c8d490a' causes SEGV error,
when 'oi = ospf_if_lookup_recv_if (ospf, iph->ip_src, ifp);' returns
NULL.

* ospf_packet.c
  * ospf_read(): change a place of calling 'ospf_verify_header()'
1 file changed