Description of problem:
While DVR is enabled traffic from VM with FIP to external host goes out via controller node rather than compute node 

Version-Release number of selected component (if applicable):
puddle 14.0-RHEL-7/2019-01-07.1 

/var/lib/config-data/neutron/etc/neutron/neutron.conf:enable_dvr=True
/var/lib/config-data/neutron/etc/neutron/plugins/ml2/ml2_conf.ini:enable_distributed_floating_ip=True


How reproducible:
Always

Steps to Reproduce:
1.Create internal network, subnet, router, connect internal and external networks to the router. Create security group with icmp and ssh allowed. Create and start VM with the security group rules applied and connected to the internal network.
2.Create floating IP and attach to the VM
3.Try to ping external host (e.g. 8.8.8.8) from the VM

Actual results:
Traffic goes out via controller/networker host.

Expected results:
Traffic goes out via compute host.

Additional info:
external_mac not set for the nat object.

[heat-admin@controller-1 containers]$ ovn-nbctl find nat type=dnat_and_snat
_uuid               : 61e0295c-e327-41f7-8324-74929b74c84c
external_ids        : {"neutron:fip_external_mac"="fa:16:3e:57:fe:70", "neutron:fip_id"="772059ef-d0c0-4798-95de-be3e75301fb6", "neutron:fip_port_id"="95381926-1945-4e85-ac84-78f2aa35676a", "neutron:revision_number"="2", "neutron:router_name"="neutron-aeca181a-dd4d-426a-a772-9388ab25a77e"}
external_ip         : "10.0.0.216"
external_mac        : []
logical_ip          : "10.0.1.10"
logical_port        : "95381926-1945-4e85-ac84-78f2aa35676a"
type                : dnat_and_snat