resource_tracker didn't report resize statue when resize a shutoff instance

[ChangBo Guo(gcb)]

We can resize a shutoff instance , but resouce_tracker doesn't include this case when judge if an instance is in resize state.
Will show a warning like
"2013-10-31 16:35:18.969 18483 WARNING nova.compute.resource_tracker [-] [instance: 813e5a44-41ba-4ee7-8b7b-442d3fc017a7] Instance not resizing, skipping migration.

[ChangBo Guo(gcb) (glongwave)]

This is code review https://review.openstack.org/#/c/55080/

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/55080
Committed: http://github.com/openstack/nova/commit/0ed493b829e8b8844b86a80da3cd70c69b1fe23a
Submitter: Jenkins
Branch: master

commit 0ed493b829e8b8844b86a80da3cd70c69b1fe23a
Author: Chang Bo Guo <email address hidden>
Date: Sun Nov 3 08:25:37 2013 -0800

    Let resource_tracker report right migration status

    A shutoff instance can be resized, but resource_tracker only think
    active instance is in migration state. This patch let it report
    right migration status.

    Closes-Bug: #1247610

    Change-Id: Ic6ce9c7d8fdecaf812831eb302186133f0ee71b1