nfp: remove incorrect mask check for vlan matching

Previously the vlan tci field was incorrectly exact matched. This patch
fixes this by using the flow dissector to populate the vlan tci field.

Fixes: 5571e8c9

 ("nfp: extend flower matching capabilities")
Signed-off-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>