datapath: pass mac_proto to ovs_vport_send

datapath: pass mac_proto to ovs_vport_send

Upstream commit:
    commit e2d9d8358cb961340ef88620b6a25ba4557033d5
    Author: Jiri Benc <jbenc@redhat.com>
    Date:   Thu Nov 10 16:28:19 2016 +0100

    openvswitch: pass mac_proto to ovs_vport_send

    We'll need it to alter packets sent to ARPHRD_NONE interfaces.

    Change do_output() to use the actual L2 header size of the packet when
    deciding on the minimum cutlen. The assumption here is that what matters is
    not the output interface hard_header_len but rather the L2 header of the
    particular packet. For example, ARPHRD_NONE tunnels that encapsulate
    Ethernet should get at least the Ethernet header.

    Signed-off-by: Jiri Benc <jbenc@redhat.com>
    Acked-by: Pravin B Shelar <pshelar@ovn.org>
    Signed-off-by: David S. Miller <davem@davemloft.net>
[Committer notes]

This is not identical to upstream, because the OVS tree is missing
upstream commit c66549ffd666 ("openvswitch: correctly fragment packet
with mpls headers")

Signed-off-by: Yi Yang <yi.y.yang@intel.com>
Signed-off-by: Joe Stringer <joe@ovn.org>