Fix log-uninitialized-stack bug in rend_service_intro_established.

Fixes bug 23490; bugfix on 0.2.7.2-alpha.

TROVE-2017-008
CVE-2017-0380
rend_service_port_config_free(rend_service_port_config_t *p)
{
  tor_free(p);
}

rend_service_port_config_free(rend_service_port_config_t *p)
{
  tor_free(p);
}
