Comment 10 for bug 1399577

Reviewed: https://review.opencontrail.org/5766
Committed: http://github.org/Juniper/contrail-vrouter/commit/e3a0755d225de698d0dbf99ca25e0735f4e40bdc
Submitter: Zuul
Branch: R1.10

commit e3a0755d225de698d0dbf99ca25e0735f4e40bdc
Author: Anand H Krishnan <email address hidden>
Date: Sun Dec 7 22:51:50 2014 -0800

Do not destroy vif's napi context, if it was not initialised during addition

If the napi structure was not initialised during interface addition, because
of errors, it should not be touched during the delete too, since doing a
netif_napi_del results in crash. However, there are no reliable checks to find
whether napi was initialised or not. Hence, for now we will check for the existance
poll function, which should have been set if the napi structure was initialised.

Closes BUG: #1399577

Change-Id: I8cf439dc53805801a5ba301f542dedb2aaa5dee2