- Do more fine-grained locking: call eventhandlers/free_entry without holding afdata wlock
- convert per-af delete_address callback to global lltable_delete_entry() and more low-level "delete this lle" per-af callback
- fix some bugs/inconsistencies in IPv4/IPv6 ifscrub procedures
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D3573