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

This reverts commit 90c7afc9.

When the commit was merged, the code used nf_ct_put() to free
the entry, but later on commit 76644232 ("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 44d6e2f2 ("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>