Instance object pci_devices and security_groups can't be None

[Chris Behrens]

The Instance object defines security_groups and pci_devices as being able to be None, however they should never be None. They are lists and should just be empty if assigned, never None.

The Instance object has code for pci_devices to account for the DB layer possibly returning None. However, it should never return None.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/47647

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/47647
Committed: http://github.com/openstack/nova/commit/39d117904783ed5cc3137b4371c087f33077a553
Submitter: Jenkins
Branch: master

commit 39d117904783ed5cc3137b4371c087f33077a553
Author: Chris Behrens <email address hidden>
Date: Fri Sep 20 21:47:09 2013 +0000

    Don't allow pci_devices/security_groups to be None

    These should never be able to be None in the Instance object. They are
    lists and can be empty, however.

    Fixes bug 1228402

    Change-Id: Id250f8921926f906e858a09759bdab888bd597b0