Comment 4 for bug 1580733

Reviewed: https://review.opencontrail.org/20225
Committed: http://github.org/Juniper/contrail-controller/commit/b961dd5be361d930f00ea0d74fe5a596366096e7
Submitter: Zuul
Branch: R3.0

commit b961dd5be361d930f00ea0d74fe5a596366096e7
Author: Naveen N <email address hidden>
Date: Sat May 14 14:44:23 2016 +0530

* Remove flow mgmt tree lookup in DB context

VRF delete notification happens in DB context,
DB and flow mgmt runs in parallel.
When VRF is deleted flow mgmt tree was lookup
to check if there are any pending flows, since
DB and flow mgmt run in parallel entries can be getting
deleted resulting deleted memory access.
Remove flow mgmt tree access, just enqueue a request
to delete VRF, which inturn verifies if all the flows
are deleted or not.
Closes-bug:#1580733

Change-Id: I976185e0a7a77d9713b284abfdebe70c8b1579bd