fix Warning

qt6-after/qt6-migrated-legatus/TetraIF/PrtCnv/PrtCnvRadioThread.cpp

@@ -1529,7 +1529,7 @@ void PrtCnvRadioThread::writeLoginLog(const N_CoPrtCnv::CoPrtCnvRadioTelegram *a
 
     
     QFile file(fileName);
-    file.open(QIODevice::Append);
+    (void)file.open(QIODevice::Append);
     file.write(logData);
     file.close();
 }