Locking for ef(4)

Hello,

Could someone look at my patch, which fixes ef(4) (locking
+ properly free allocated memory):

http://freebsd.czest.pl/dunstan/FreeBSD/diff.locking.if_ef.c
(PR: kern/85086).

Please remember that your src/sys/net/if.c version has to be
at least 1.244.

-- 
* Wojciech A. Koszek && dunstan_at_FreeBSD.czest.pl