make unshelving and rescuing as io state which will be counted for ioops filter

[jichenjc]

IOopsFilter will take instance in following state
task_states.RESIZE_MIGRATING, task_states.REBUILDING, task_states.RESIZE_PREP, task_states.IMAGE_SNAPSHOT, task_states.IMAGE_BACKUP

into consideration ,if the instance on this host exceed the maximum number of instance allowed to do I/O
the scheduler will fail

we need to take UNSHELVING and RESCUING into consideration

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/82044

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/82407

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/82407
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=2318f9ba64b4c793eb913330b862d608d86c03b2
Submitter: Jenkins
Branch: master

commit 2318f9ba64b4c793eb913330b862d608d86c03b2
Author: jichenjc <email address hidden>
Date: Sat Mar 22 22:30:09 2014 +0800

    Add UNSHELVING and RESCUING into IoOPSFilter consideration state

    IoOpsFilter will take instance in following state
    task_states.RESIZE_MIGRATING, task_states.REBUILDING, task_states.RESIZE_PREP,
    task_states.IMAGE_SNAPSHOT, task_states.IMAGE_BACKUP
    into consideration ,if the instance on this host exceed the maximum
    number of instance allowed to do I/O the scheduler will fail on the host

    UNSHELVING and RESCUING are also I/O related so IoOps need to include them

    Change-Id: I141470254c824e7e57e6734ae0e016c432b85c00
    Closes-Bug: #1295558