The 8139cp driver did VLAN unregistration incorrectly.
It disables VLAN completely when the first VID is unregistered. It
should instead disable VLAN when the group is unregistered by calling
cp_vlan_rx_register with a NULL grp.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>