NSX plugin unable to list gateway devices

[Salvatore Orlando]

A small error has been introduced in get_gateway_devices, causing the method fail everytime.
It tried to pass 'fields' to _get_collection_query, but this method does not have the fields keyword parameter.

The error went undetected as db-level unit tests do not cover get_gateway_devices.

The error affect icehouse only.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/86748

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/86748
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=3753622406a85daf50d2f7f1a9a21ff351560684
Submitter: Jenkins
Branch: master

commit 3753622406a85daf50d2f7f1a9a21ff351560684
Author: Salvatore Orlando <email address hidden>
Date: Thu Apr 10 16:55:51 2014 -0700

    NSX plugin: fix get_gateway_devices

    Fixes the error and adds relevant unit tests.
    Also fixes get_gateway_devices signature for allowing
    paging and sorting.

    Closes-Bug: 1306301

    Change-Id: Icb52a764e111365beaf4dc4fb4a5b8970a6cf887