l3_agent: ri.internal_ports.append/removed should be called only if internal_network_added/removed succeed.

[Jian Wen]

How to reproduce:
  See the test cases in the following patch.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/58942

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/58942
Committed: http://github.com/openstack/neutron/commit/dd71021347f782608575d551f2329715c00546ce
Submitter: Jenkins
Branch: master

commit dd71021347f782608575d551f2329715c00546ce
Author: Jian Wen <email address hidden>
Date: Wed Nov 27 22:23:26 2013 +0800

    l3_agent: make process_router more robust

    If internal_network_added/removed fails, _sync_routers_task will call
    process_router to do fault recovery. Because the port is already
    added/removed to/from ri.internal_ports, internal_network_added or
    internal_network_removed will not be called again.

    The patch fix this issue by calling ri.internal_ports.append/removed
    only if internal_network_added/removed succeed. Without the patch,
    the added testcases would fail.

    Change-Id: I2d2e004caa670c1624257c1d7ccc900438b42d08
    Co-Authored-By: Hirofumi Ichihara <email address hidden>
    Closes-Bug: #1255871