* {bsdi3,freebsd2}/sys/netinet/udp_usrreq.c: fix data corruption   when multiple listening socket exists for udp multicast.
* {bsdi3,freebsd2}/sys/netinet/udp_usrreq.c: fix data corruption
  when multiple listening socket exists for udp multicast.

MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame