datapath: Revert "datapath: Fix template leak in error cases."

datapath: Revert "datapath: Fix template leak in error cases."

Upstream commit:
    commit 7f6d6558ae44bc193eb28df3617c364d3bb6df39
    Author: Flavio Leitner <fbl@redhat.com>
    Date:   Fri Sep 28 14:55:34 2018 -0300

    Revert "openvswitch: Fix template leak in error cases."
    This reverts commit 90c7afc.

    When the commit was merged, the code used nf_ct_put() to free
    the entry, but later on commit 7664423 ("openvswitch: Free
    tmpl with tmpl_free.") replaced that with nf_ct_tmpl_free which
    is a more appropriate. Now the original problem is removed.

    Then 44d6e2f ("net: Replace NF_CT_ASSERT() with WARN_ON().")
    replaced a debug assert with a WARN_ON() which is trigged now.

    Signed-off-by: Flavio Leitner <fbl@redhat.com>
    Acked-by: Joe Stringer <joe@ovn.org>
    Signed-off-by: David S. Miller <davem@davemloft.net>
This patch backports this upstream patch to OVS.

Acked-by: Flavio Leitner <fbl@sysclose.org>
Signed-off-by: Yifeng Sun <pkusunyifeng@gmail.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>