iscsi transport support broken due to use of incorrect oslo_config choices support

[Anish Bhatt]

This changeset https://git.openstack.org/cgit/openstack/nova/commit/?id=ed9f1b8b43161c1bc637022aaf67fb5f7a21b0f6

forces iscsi_iface to be one out of ('be2iscsi', 'bnx2i', 'cxgb3i', 'cxgb4i', 'qla4xxx', 'ocs'), this is incorrect. This is confusing iscsi_transport, an open-iscsi parameter with iscsi_iface, which is the generated iface file actually needed for iscsi_iface support.

This also directly contradicts the explanation given right below the parameter, and breaks iface support unless you create an iface with the same name as the transport when the default naming scheme will always follow 'transport_name.hwaddress'

I had previously pushed another changeset meant to avoid the very same (https://github.com/openstack/nova/commit/3b8a2cf781d43d0b6937ec66aff5f37657f625ed) which also seems to have been ignored.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/193414
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=66b9c2ceaea3decc117cfe7d326a92bf2bdd169b
Submitter: Jenkins
Branch: master

commit 66b9c2ceaea3decc117cfe7d326a92bf2bdd169b
Author: Anish Bhatt <email address hidden>
Date: Thu Jun 18 22:52:04 2015 -0700

    libvirt : remove broken olso_config choices option

    Changeset ed9f1b8b restricted the allowed options for iscsi_iface
    to the allowed transports mentioned in the help text. iface &
    transport are distinct entities for open-iscsi, and an iface is
    generally a mix of transport plus an underlying interface, hence
    this change was incorrect. This breaks transport support and is
    generally incorrect, hence reverting

    Closes-Bug:1466730
    Change-Id: I687fb9c95133dbbb193004df44794404b58ca692