ensure removed devices get treated on resyncs for Mlnx Agent

[Irena Berezovsky]

Add to Mellanox Agent the the same handling as https://review.openstack.org/#/c/77842/ does for LinuxBridgeAgent to handle removed devices cleanup

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/94888

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/94888
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=598e14cfdeb0162a7b1ef088f32076d063c55526
Submitter: Jenkins
Branch: master

commit 598e14cfdeb0162a7b1ef088f32076d063c55526
Author: Roey Chen <email address hidden>
Date: Tue May 20 17:10:17 2014 +0300

    MLNX Agent: ensure removed ports get treated on resyncs

    This patch ensures that removed ports will be cleaned up properly if exception
    occurs in the daemon_loop.
    It does the same for the mlnx-agent as was done for the lb-agent in
    Ieada34ad315c0c29aa8462ebf041a448fde007b8.

    Refactoring the daemon_loop and scan_ports in a way that -
    If there's an exception, the ports that were flagged for cleaning will
    be retreated in the following iteration,
    unlike previous exception handling, where only existing ports
    were treated in the following iteration.

    Closes-Bug: 1287648
    Change-Id: I3af505773aa3fdc0d17f2079ac1f1b3e93bb64a3
    Signed-off-by: Roey Chen <email address hidden>