openvswitch: Do not trigger events for unconfirmed connections.

Receiving change events before the 'new' event for the connection has
been received can be confusing.  Avoid triggering change events for
setting conntrack mark or labels before the conntrack entry has been
confirmed.

Fixes: 182e3042 ("openvswitch: Allow matching on conntrack mark")
Fixes: c2ac6673

 ("openvswitch: Allow matching on conntrack label")
Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Acked-by: Joe Stringer <joe@ovn.org>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>