make LF sampling ACK to fix USB timing issue in em410xwatch

client/cmdlf.c

@@ -266,6 +266,7 @@ int CmdLFRead(const char *Cmd)
     return 0;
   }
   SendCommand(&c);
+  WaitForResponse(CMD_ACK);
   return 0;
 }
 

client/cmdmain.c

@@ -125,6 +125,7 @@ void UsbCommandReceived(UsbCommand *UC)
       for(i=0; i<48; i++) sample_buf[i] = UC->d.asBytes[i];
       received_command = UC->cmd;
       return;
+    case CMD_ACQUIRE_RAW_ADC_SAMPLES_125K:
     case CMD_DOWNLOADED_SIM_SAMPLES_125K:
       if (UC->cmd != CMD_ACK) goto unexpected_response;
       // got ACK