Core: Remove one IEditorFactory::addMimeType overload

Not overly useful in the times of QT_RESTRICTED_CAST_FROM_ASCII

Change-Id: I87032b1da9cc4e8205d2a9c8596bc9ba832acf30
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/imageviewer/imageviewerfactory.cpp

@@ -42,7 +42,7 @@ ImageViewerFactory::ImageViewerFactory()
 
     const QList<QByteArray> supportedMimeTypes = QImageReader::supportedMimeTypes();
     for (const QByteArray &format : supportedMimeTypes)
-        addMimeType(format.constData());
+        addMimeType(QString::fromLatin1(format));
 }
 
 } // namespace Internal