freebsd: compatibility fix for looking for CMSG_DATA
freebsd: compatibility fix for looking for CMSG_DATA

Patch contributed by Sven Wegener

heftig/avahi,Distrotech/avahi,heftig/avahi-1,catta-x/catta,heftig/avahi-1,Distrotech/avahi,heftig/avahi,gloryleague/avahi,Kisensum/xmDNS-avahi,catta-x/catta,lathiat/avahi,Distrotech/avahi,lathiat/avahi,heftig/avahi-1,everbase/catta,gloryleague/avahi,Kisensum/xmDNS-avahi,heftig/avahi,gloryleague/avahi,Kisensum/xmDNS-avahi,heftig/avahi-1,lathiat/avahi,Distrotech/avahi,Kisensum/xmDNS-avahi,Kisensum/xmDNS-avahi,gloryleague/avahi,Distrotech/avahi,heftig/avahi,everbase/catta,catta-x/catta,heftig/avahi-1,heftig/avahi,lathiat/avahi,Kisensum/xmDNS-avahi,everbase/catta,lathiat/avahi,heftig/avahi,heftig/avahi-1,lathiat/avahi,gloryleague/avahi,Distrotech/avahi,gloryleague/avahi