* SRD_LOG_WARN, SRD_LOG_INFO, SRD_LOG_DBG, or SRD_LOG_SPEW).
*
* @return SRD_OK upon success, SRD_ERR_ARG upon invalid loglevel.
* SRD_LOG_WARN, SRD_LOG_INFO, SRD_LOG_DBG, or SRD_LOG_SPEW).
*
* @return SRD_OK upon success, SRD_ERR_ARG upon invalid loglevel.