Revert "openvswitch: switch to per-action label counting in conntrack"

In the Linux kernel, the following vulnerability has been resolved:

Revert "openvswitch: switch to per-action label counting in conntrack"

Currently, ovs_ct_set_labels() is only called for confirmed conntrack

entries (ct) within ovs_ct_commit(). However, if the conntrack entry

does not have the labels_ext extension, attempting to allocate it in

ovs_ct_get_conn_labels() for a confirmed entry triggers a warning in

nf_ct_ext_add():

WARN_ON(nf_ct_is_confirmed(ct));

This happens when the conntrack entry is created externally before OVS

increments net->ct.labels_used. The issue has become more likely since

commit fcb1aa5163b1 ("openvswitch: switch to per-action label counting

in conntrack"), which changed to use per-action label counting and

increment net->ct.labels_used when a flow with ct action is added.

Since there’s no straightforward way to fully resolve this issue at the

moment, this reverts the commit to avoid breaking existing use cases.