Consider the following scenario:
1. A StatefulSet Pod with random IP address allocation is deleted
and soon kube-ovn-contrller is restarted;
2. kube-ovn-controller initailizes IPAM on startup and no IPAM record
for the deleted StatefuleSet Pod is created;
3. A new StatefulSet Pod with the same name is created and
kube-ovn-controller assigns a new IP address to it.