Bsongis/issue 4400 (#4425)

* Cosmetics before fixing #4400

* Cosmetics before fixing #4400

* Now one more conversion issue (SF => SH sources conversion from X9D to X7)

I don't know what is exactly the conversion issue as I don't have the original EEPROM, but I used this one for my tests, so I fix it

* Now we display correctly the corrupted mixers list so that copy/paste will work correctly (it was not consistent)

+ some cosmetics

* Test removed too quickly

* One global removed ;)

companion/src/storage/storage.cpp

@@ -118,8 +118,9 @@ bool convertEEprom(const QString & sourceEEprom, const QString & destinationEEpr
   }
   
   QFile destinationFile(destinationEEprom);
-  if (!destinationFile.open(QIODevice::WriteOnly))
+  if (!destinationFile.open(QIODevice::WriteOnly)) {
     return false;
+  }
   
   int result = destinationFile.write(eeprom.constData(), size);
   destinationFile.close();