Move the vlan_tci field up by two bytes in the mbuf data structure. This
has two effects:
* Ensures the the ixgbe vector driver places the vlan tag in the correct
place in the mbuf.
* Allows a second vlan tag field, if one is added in the future, to be
placed after the existing vlan field, rather than before.
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com> Acked-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>