Comment 9 for bug 1770422

Reviewed: https://review.opencontrail.org/43021
Committed: http://github.com/Juniper/contrail-controller/commit/e77a3b7c2f69a29bfd56bd6d9bc22a63d5ca42f5
Submitter: Zuul v3 CI (<email address hidden>)
Branch: master

commit e77a3b7c2f69a29bfd56bd6d9bc22a63d5ca42f5
Author: Anda Nicolae <email address hidden>
Date: Thu May 10 17:47:12 2018 +0300

Coverity issues in contrail-controller/pkt0_interface_base.cc

I have run Coverity on branch R5.0 and it reported the following
issue in contrail-controller/pkt0_interface_base.cc:

- double_free: Calling ~Pkt0Interface frees pointer this->read_buff_
which has already been freed in pkt0_interface_base.cc:~Pkt0RawInterface()

Indeed, Pkt0RawInterface inherits Pkt0Interface. read_buff_ pointer is freed
in both the destructor of Pkt0Interface and in the destructor of Pkt0RawInterface.
Solution is to free read_buff_ only in the destructor of the base class: Pkt0Interface.

Change-Id: Idfd6ce06a9cc561fb9da76ce0aaf985e9c51ab71
Closes-Bug: #1770422
Signed-off-by: Anda Nicolae <email address hidden>