network drivers: eliminate unneeded kill_vid code

Many drivers had code that did kill_vid, but they weren't doing vlan
filtering. With new API the stub is unneeded unless device sets
NETIF_F_HW_VLAN_FILTER.

Bad habit: I couldn't resist fixing a couple of nearby style things
in acenic, and forcedeth.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>