Original code in 5.0.16:

        if (ssidLen || (memcmp(pScanCfgOut->specificBSSID,
                               &zeroMac, sizeof(zeroMac)) != 0)) {
            *pMaxChanPerScan = MRVDRV_MAX_CHANNELS_PER_SCAN;
            *pFilteredScan = TRUE;
        }

Code in current libertas:

                if (compare_ether_addr(user_cfg->bssid, &zeromac[0]) != 0) {
                        numchannels = MRVDRV_MAX_CHANNELS_PER_SCAN;
                        filteredscan = 1;
                }