net: consolidate 8021q tagging

Now that VLAN packets are tagged in dev_hard_start_xmit()
at the bottom of the stack we no longer need to tag them
in the 8021Q module (Except in the !VLAN_FLAG_REORDER_HDR
case).

This allows the accel path and non accel paths to be consolidated.
Here the vlan_tci in the skb is always set and we allow the
stack to add the actual tag in dev_hard_start_xmit().

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>