netdev-offload-dpdk: Fix Ethernet matching for type only.

netdev-offload-dpdk: Fix Ethernet matching for type only.

For OVS rule of the form "eth type is 0x1234 / end", rule is offloaded
in the form of "eth / end", which is incorrect. Fix it.

Fixes: e8a2b5bf92bb ("netdev-dpdk: implement flow offload with rte flow")
Signed-off-by: Eli Britstein <elibr@mellanox.com>
Reviewed-by: Roni Bar Yanai <roniba@mellanox.com>
Acked-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>