get_snat_port_for_internal_port called twice when an interface is added or removed by the l3 agent in the case of DVR routers.

[Swaminathan Vasudevan]

get_snat_port_for_internal_port retrieves the internal snat port created for each router interface added to a DVR router.
But this function is called twice in the L3 agent code.

for every interface add or delete to the router, it is called by the 'dvr_local_router.py' and again it is called by the 'dvr_edge_router.py'.

This can be reduced to a single call to improve the controll plane performance.

[OpenStack Infra (hudson-openstack)]

Change abandoned by Armando Migliaccio (<email address hidden>) on branch: master
Review: https://review.openstack.org/225523
Reason: This review is > 4 weeks without comment, and failed Jenkins the last time it was checked. We are abandoning this for now. Feel free to reactivate the review by pressing the restore button and leaving a 'recheck' comment to get fresh test results.

[Brian Haley (brian-haley)]

Closing as old bug and patch was rejected. Please re-open if necessary. Thanks.