Comment 19 for bug 1768322

Reviewed: https://review.opencontrail.org/44445
Committed: http://github.com/Juniper/contrail-controller/commit/4e86c5268312c9471621d3b0850d6db63e10d5e5
Submitter: Zuul v3 CI (<email address hidden>)
Branch: master

commit 4e86c5268312c9471621d3b0850d6db63e10d5e5
Author: sangarshp <email address hidden>
Date: Sun Jul 8 18:24:35 2018 +0530

Check Gen id for processing recompute events for flows

it is possible that enqueued forward flow become reverse flow when
flows get evicted from vrouter and traffic is received for reverse flow,

made changes to pass gen_id also when flow is enqueued for recompute
and when it gets processed for recompute , check whether gen id present
in the event and gen id of flow matches, if it does not match,
ignore the event.

Change-Id: Ib647a157ecd852a3520a90ffba5f392ae3b33e1e
Closes-Bug: #1768322