[VLAN]: Fix device refcount bug.

If you rmmod a network device that is in a vlan, the system hangs waiting
for the refcount to go to zero, because it is -1.  The problem is that the
vlan notifier does an extra dev_put in NETDEV_UNREGISTER case of notifier.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@redhat.com>

net/8021q/vlan.c

@@ -625,7 +625,6 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event,
 			ret = unregister_vlan_dev(dev,
 						  VLAN_DEV_INFO(vlandev)->vlan_id);
 
-			dev_put(vlandev);
 			unregister_netdevice(vlandev);
 
 			/* Group was destroyed? */