dont put pfsync packets on the wire if no syncdev is specified. issues reported by david@
dont put pfsync packets on the wire if no syncdev is specified. issues
reported by david@

an earlier version of this was ok mcbride@
ok deraadt@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars