Comment 2 for bug 1388221

Reviewed: https://review.opencontrail.org/4322
Committed: http://github.org/Juniper/contrail-sandesh/commit/421e705ef085d6f2b225bf1d3b27beb5c423f8da
Submitter: Zuul
Branch: master

commit 421e705ef085d6f2b225bf1d3b27beb5c423f8da
Author: Megh Bhatt <email address hidden>
Date: Tue Nov 4 18:14:34 2014 -0800

TcpSession::Send() and TcpSession::WriteReady() can be called from
concurrent threads and hence just having an atomic bool to update
the send status is not enough to guarantee that the correct send
status is finally set. A recent change in SandeshWriter removed
the mutex acquired before called TcpSession::Send() and updating the
send status and used to update the send status in the
TcpSession::WriteReady() callback. This change reverts back to
using the mutex in SandeshWriter.
Closes-Bug: #1388221

Change-Id: Ibb560021d6a0d8963db6284f1d722a974cb45be2