Change uses of {to,from}Ascii to {to,from}Latin1

This operation should be a no-op anyway, since at this point in time,
the fromAscii and toAscii functions simply call their fromLatin1 and
toLatin1 counterparts.

Task-number: QTBUG-21872
Change-Id: Ic591779a3431999c007fb0ff362c7e25ce54097e
Reviewed-by: Jonas Rabbe <jonas.rabbe@gmail.com>

src/multimedia/video/qvideoframe.cpp

@@ -930,7 +930,7 @@ QDebug operator<<(QDebug dbg, QVideoFrame::PixelFormat pf)
             return dbg.nospace() << "Format_CameraRaw";
 
         default:
-            return dbg.nospace() << QString(QLatin1String("UserType(%1)" )).arg(int(pf)).toAscii().constData();
+            return dbg.nospace() << QString(QLatin1String("UserType(%1)" )).arg(int(pf)).toLatin1().constData();
     }
 }