Form submission handler for system_logging_settings().
syslog_form_system_logging_settings_alter()
function syslog_logging_settings_submit($form, &$form_state) {
config('syslog.settings')
->set('identity', $form_state['values']['syslog_identity'])
->set('facility', $form_state['values']['syslog_facility'])
->set('format', $form_state['values']['syslog_format'])
->save();
}