Compute manager NotFound exception inconsistent

[Kyle L. Henderson]

Nova compute manager calls the compute driver to get the instance state in both _get_power_state() and _query_driver_power_state_and_sync(), however it's inconsistent in what exception is expected when an instance does not exist.

In _get_power_state() it expects NotFound and returns NOSTATE

In _query_driver_power_state_and_sync() it expects InstanceNotFound and uses NOSTATE as the current instance state.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/140829

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/140829
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=a0bfd6669899a387e230a991181eb2e3833e17c2
Submitter: Jenkins
Branch: master

commit a0bfd6669899a387e230a991181eb2e3833e17c2
Author: Joe Gordon <email address hidden>
Date: Wed Dec 10 12:04:19 2014 -0800

    Catch more specific exception in _get_power_state

    _get_power_state expects InstanceNotFound and not its parent exception
    NotFound. So catch the more specific exception to make the code
    consistent and so we don't hide other issues.

    Change-Id: I64b79d954f1b48d073b0a4662a58c803425c015f
    Closes-Bug: #1400764