Fill sin6_scope_id in sockaddr_in6 before passing it from the kernel to
userland via routing socket or sysctl.  This eliminates the following
KAME-specific sin6_scope_id handling routine from each userland utility:

 sin6.sin6_scope_id = ntohs(*(u_int16_t *)&sin6.sin6_addr.s6_addr[2]);

This behavior can be controlled by net.inet6.ip6.deembed_scopeid.  This is
set to 1 by default (sin6_scope_id will be filled in the kernel).

Obtained from:	FreeBSD svn rev 243187