COLO: Shutdown related socket fd while do failover

COLO: Shutdown related socket fd while do failover

If the net connection between primary host and secondary host breaks
while COLO/COLO incoming threads are doing read() or write().
It will block until connection is timeout, and the failover process
will be blocked because of it.

So it is necessary to shutdown all the socket fds used by COLO
to avoid this situation. Besides, we should close the corresponding
file descriptors after failvoer BH shutdown them,
Or there will be an error.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1484657864-21708-3-git-send-email-zhang.zhanghailiang@huawei.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>