ixgbe: Always tag VLAN tagged packets

This change is meant to fix the patch:
	ixgbe: Cleanup FCOE and VLAN handling in xmit_frame_ring
And can be rolled into it if needed.

What this fixes is that VLAN tagged packets were not being tagged if they
were prio 7 which matches up with TC_PRIO_CONTROL.  In order to fix it I am
just setting things up so that we always tag VLAN tagged packets.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>