Description of problem:
When migrating sr-iov nodes that don't have OVS agent running the migration steps fail and will not continue with migration tasks on the sriov nodes. This will lead to situation where nodes are left in inconsistent state with uncompleted migration.

Version-Release number of selected component (if applicable):


How reproducible:
100%

Steps to Reproduce:
1. Run OVN migration with SR-IOV nodes
2.
3.

Actual results:
Migration itself passes but sr-iov nodes are not migrated and have some leftovers.

Expected results:
sr-iov nodes have no leftovers

Additional info:
Perhaps sriov nodes don't need to run any steps during the migration.

br-migration is present on sr-iov nodes
OVN was not activated

TASK [stop-agents : stop and disable ovs services and healthchecks] **************************************************************************************************************
task path: /home/stack/ovn_migration/playbooks/roles/stop-agents/tasks/cleanup.yml:2
Wednesday 06 October 2021  18:19:17 +0000 (0:00:00.648)       0:00:08.091 *****
META: noop
META: noop
META: noop
failed: [computesriov-0] (item=tripleo_neutron_ovs_agent_healthcheck.timer) => {"ansible_loop_var": "item", "changed": false, "item": "tripleo_neutron_ovs_agent_healthcheck.timer
", "msg": "Could not find the requested service tripleo_neutron_ovs_agent_healthcheck.timer: host"}
failed: [computesriov-1] (item=tripleo_neutron_ovs_agent_healthcheck.timer) => {"ansible_loop_var": "item", "changed": false, "item": "tripleo_neutron_ovs_agent_healthcheck.timer
", "msg": "Could not find the requested service tripleo_neutron_ovs_agent_healthcheck.timer: host"}
failed: [computesriov-0] (item=tripleo_neutron_ovs_agent_healthcheck.service) => {"ansible_loop_var": "item", "changed": false, "item": "tripleo_neutron_ovs_agent_healthcheck.ser
vice", "msg": "Could not find the requested service tripleo_neutron_ovs_agent_healthcheck.service: host"}
failed: [computesriov-1] (item=tripleo_neutron_ovs_agent_healthcheck.service) => {"ansible_loop_var": "item", "changed": false, "item": "tripleo_neutron_ovs_agent_healthcheck.ser
vice", "msg": "Could not find the requested service tripleo_neutron_ovs_agent_healthcheck.service: host"}
failed: [computesriov-0] (item=tripleo_neutron_ovs_agent.service) => {"ansible_loop_var": "item", "changed": false, "item": "tripleo_neutron_ovs_agent.service", "msg": "Service i
s in unknown state", "status": {}}
failed: [computesriov-1] (item=tripleo_neutron_ovs_agent.service) => {"ansible_loop_var": "item", "changed": false, "item": "tripleo_neutron_ovs_agent.service", "msg": "Service i
s in unknown state", "status": {}}