for (i = 0; i < serial->event_set->count; i++)
if (sr_session_source_remove_pollfd(session, &serial->pollfds[i]) != SR_OK)
return SR_ERR;
for (i = 0; i < serial->event_set->count; i++)
if (sr_session_source_remove_pollfd(session, &serial->pollfds[i]) != SR_OK)
return SR_ERR;