Comment 0 for bug 1713783

Description
===========
In case of a failed evacuation attempt the status of the migration is 'accepted' instead of 'failed' so the manager tries to delete the instance.

Steps to reproduce
==================
The following functional test reproduces the bug: https://review.openstack.org/#/c/498482/
What it does: initiate evacuation when no valid host is available and evacuation fails, but nova manager still tries to delete the instance.
Logs:

    2017-08-29 19:11:15,751 ERROR [oslo_messaging.rpc.server] Exception during message handling
    NoValidHost: No valid host was found. There are not enough hosts available.
    2017-08-29 19:11:16,103 INFO [nova.tests.functional.test_servers] Running periodic for compute1 (host1)
    2017-08-29 19:11:16,115 INFO [nova.api.openstack.placement.requestlog] 127.0.0.1 "GET /placement/resource_providers/4e8e23ff-0c52-4cf7-8356-d9fa88536316/aggregates" status: 200 len: 18 microversion: 1.1
    2017-08-29 19:11:16,120 INFO [nova.api.openstack.placement.requestlog] 127.0.0.1 "GET /placement/resource_providers/4e8e23ff-0c52-4cf7-8356-d9fa88536316/inventories" status: 200 len: 401 microversion: 1.0
    2017-08-29 19:11:16,131 INFO [nova.api.openstack.placement.requestlog] 127.0.0.1 "GET /placement/resource_providers/4e8e23ff-0c52-4cf7-8356-d9fa88536316/allocations" status: 200 len: 152 microversion: 1.0
    2017-08-29 19:11:16,138 INFO [nova.compute.resource_tracker] Final resource view: name=host1 phys_ram=8192MB used_ram=1024MB phys_disk=1028GB used_disk=1GB total_vcpus=10 used_vcpus=1 pci_stats=[]
    2017-08-29 19:11:16,146 INFO [nova.api.openstack.placement.requestlog] 127.0.0.1 "GET /placement/resource_providers/4e8e23ff-0c52-4cf7-8356-d9fa88536316/aggregates" status: 200 len: 18 microversion: 1.1
    2017-08-29 19:11:16,151 INFO [nova.api.openstack.placement.requestlog] 127.0.0.1 "GET /placement/resource_providers/4e8e23ff-0c52-4cf7-8356-d9fa88536316/inventories" status: 200 len: 401 microversion: 1.0
    2017-08-29 19:11:16,152 INFO [nova.tests.functional.test_servers] Running periodic for compute2 (host2)
    2017-08-29 19:11:16,163 INFO [nova.api.openstack.placement.requestlog] 127.0.0.1 "GET /placement/resource_providers/531b1ce8-def1-455d-95b3-4140665d956f/aggregates" status: 200 len: 18 microversion: 1.1
    2017-08-29 19:11:16,168 INFO [nova.api.openstack.placement.requestlog] 127.0.0.1 "GET /placement/resource_providers/531b1ce8-def1-455d-95b3-4140665d956f/inventories" status: 200 len: 401 microversion: 1.0
    2017-08-29 19:11:16,176 INFO [nova.api.openstack.placement.requestlog] 127.0.0.1 "GET /placement/resource_providers/531b1ce8-def1-455d-95b3-4140665d956f/allocations" status: 200 len: 54 microversion: 1.0
    2017-08-29 19:11:16,184 INFO [nova.compute.resource_tracker] Final resource view: name=host2 phys_ram=8192MB used_ram=512MB phys_disk=1028GB used_disk=0GB total_vcpus=10 used_vcpus=0 pci_stats=[]
    2017-08-29 19:11:16,192 INFO [nova.api.openstack.placement.requestlog] 127.0.0.1 "GET /placement/resource_providers/531b1ce8-def1-455d-95b3-4140665d956f/aggregates" status: 200 len: 18 microversion: 1.1
    2017-08-29 19:11:16,197 INFO [nova.api.openstack.placement.requestlog] 127.0.0.1 "GET /placement/resource_providers/531b1ce8-def1-455d-95b3-4140665d956f/inventories" status: 200 len: 401 microversion: 1.0
    2017-08-29 19:11:16,198 INFO [nova.tests.functional.test_servers] Finished with periodics
    2017-08-29 19:11:16,255 INFO [nova.api.openstack.requestlog] 127.0.0.1 "GET /v2.1/6f70656e737461636b20342065766572/servers/5058200c-478e-4449-88c1-906fdd572662" status: 200 len: 1875 microversion: 2.53 time: 0.056198
    2017-08-29 19:11:16,262 INFO [nova.api.openstack.requestlog] 127.0.0.1 "GET /v2.1/6f70656e737461636b20342065766572/os-migrations" status: 200 len: 373 microversion: 2.53 time: 0.004618
    2017-08-29 19:11:16,280 INFO [nova.api.openstack.requestlog] 127.0.0.1 "PUT /v2.1/6f70656e737461636b20342065766572/os-services/c269bc74-4720-4de4-a6e5-889080b892a0" status: 200 len: 245 microversion: 2.53 time: 0.016442
    2017-08-29 19:11:16,281 INFO [nova.service] Starting compute node (version 16.0.0)
    2017-08-29 19:11:16,296 INFO [nova.compute.manager] Deleting instance as it has been evacuated from this host