migrate server doesn't raise correct exception

[huangtianhua]

Migrate a non existent server throws HTTPBadRequest exception ,the correct is InstanceNotFound exception.
live-migrate has the same problem.

The other server actions throw InstanceNotFound exception.

I think it's a bug.

[Davanum Srinivas (DIMS) (dims-v)]

review is here https://review.openstack.org/#/c/51339/

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/51339
Committed: http://github.com/openstack/nova/commit/103db29c224909cd260f1619a0a4578e172f6649
Submitter: Jenkins
Branch: master

commit 103db29c224909cd260f1619a0a4578e172f6649
Author: huangtianhua <[e-mail]>
Date: Sat Oct 12 11:00:03 2013 +0800

    migrate server doesn't raise correct exception

    Currently a BadRequest is raised for the migrate and live-migrate API
    operations when the given instance isn't found. This patch changes the
    APIs to raise a InstanceNotFound instead to be consistent with the other
    admin action APIs which hit the same type of error.

    Closes-Bug: #1239038

    Change-Id: I28cd367c5885481ea19ace43855b2518a2afd955