fill sin6_scope_id for linklocal udp packets.
fill sin6_scope_id for linklocal udp packets.

From: 4d0e867c575fcaf681b9f2b14527dff1a94b7d40@dti.ad.jp

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