Comment 24 for bug 1768322

Reviewed: https://review.opencontrail.org/44843
Committed: http://github.com/Juniper/contrail-controller/commit/c065431169a0e3c9bdfc19d1d9ab60547bee1c11
Submitter: Zuul (<email address hidden>)
Branch: R3.2.3.x

commit c065431169a0e3c9bdfc19d1d9ab60547bee1c11
Author: sangarshp <email address hidden>
Date: Mon Jul 9 08:34:36 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 enquwqued 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
(cherry picked from commit e5df8e0a1c8c59a487f878942802d3eb36a323d2)