Comment 2 for bug 935230

Dah! There's indeed a bug here, I must have got confused while porting those last changes:

                if (usb[idProduct]->value != NULL || usb[idVendor]->value != NULL) {
                        modeswitch_log(" Essential attributes are missing, continue wait ...\n");
                        continue;
                }

^^ is obviously wrong. I'll fix this ASAP.