hang at 'deploying' state if can not get root_uuid

[Haomeng,Wang]

https://github.com/openstack/ironic/blob/80670140b19e1d5daf9c7aebd4c90771667d8e66/ironic/drivers/modules/pxe.py#L471

        if not root_uuid:
            return

Here should raise exception to avoid hang at 'deploying' state if we can not get the root_uuid for some case.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/143919

[John Stafford (john-stafford)]

Hi Haomeng,

Are you still working this, or is it abandoned/waiting for someone else to pick it up??

[Haomeng,Wang (whaom)]

Yes, John, I am back from my new year vacation, so will pick this up soon, thanks for your kindly reminder.

[John Stafford (john-stafford)]

Thank you very much for the response Haomeng. Hope you had a fun New Year :-)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/143919
Committed: https://git.openstack.org/cgit/openstack/ironic/commit/?id=75fbef22b6d9a58687a58a9413df21bd2fa90a00
Submitter: Jenkins
Branch: master

commit 75fbef22b6d9a58687a58a9413df21bd2fa90a00
Author: Ramakrishnan G <email address hidden>
Date: Thu Mar 19 10:28:19 2015 +0000

    Fail deploy if root uuid or disk id isn't available

    Makes the vendor passthrus pass_deploy_info of pxe
    and ilo deploys to fail the deploy if root uuid or
    disk id isn't available.

    Closes-Bug: 1405519
    Change-Id: Icb4771ad4ec2b8a32890e8324a9d23747225a909