datapath: Backport: openvswitch: Fix serialization of non-masked set actions.

datapath: Backport: openvswitch: Fix serialization of non-masked set actions.

I found this missing commit while checking diff against upstream OVS.

Upstream Commit msg:
    Set actions consist of a regular OVS_KEY_ATTR_* attribute nested inside
    of a OVS_ACTION_ATTR_SET action attribute. When converting masked actions
    back to regular set actions, the inner attribute length was not changed,
    ie, double the length being serialized. This patch fixes the bug.

    Fixes: 83d2b9b ("net: openvswitch: Support masked set actions.")
    Signed-off-by: Joe Stringer <joestringer@nicira.com>
    Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
Upstream: f4f8e738505 ("openvswitch: Fix serialization of non-masked set
actions")
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Joe Stringer <joe@ovn.org>