ping_server: Always close the socket
ping_server: Always close the socket

The socket is currently left unclosed if an error happens.

Change-Id: I1f3db6c85f65dd218a32d205860c8a1bb0456558

stevelle/glance,openstack/glance,rajalokan/glance,openstack/glance,rajalokan/glance,stevelle/glance,openstack/glance