datapath: set network header correctly on key extract

datapath: set network header correctly on key extract

Upstream commit:
    commit f7d49bce8e741e1e6aa14ce4db1b6cea7e4be4e8
    Author: Jiri Benc <jbenc@redhat.com>
    Date:   Fri Sep 30 19:08:05 2016 +0200

    openvswitch: mpls: set network header correctly on key extract

    After the 48d2ab609b6b ("net: mpls: Fixups for GSO"), MPLS handling in
    openvswitch was changed to have network header pointing to the start of the
    MPLS headers and inner_network_header pointing after the MPLS headers.

    However, key_extract was missed by the mentioned commit, causing incorrect
    headers to be set when a MPLS packet just enters the bridge or after it is
    recirculated.

    Fixes: 48d2ab609b6b ("net: mpls: Fixups for GSO")
    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>
Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>