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/qabstractvideobuffer.cpp

@@ -232,7 +232,7 @@ QDebug operator<<(QDebug dbg, QAbstractVideoBuffer::HandleType type)
     case QAbstractVideoBuffer::QPixmapHandle:
         return dbg.nospace() << "QPixmapHandle";
     default:
-        return dbg.nospace() << QString(QLatin1String("UserHandle(%1)")).arg(int(type)).toAscii().constData();
+        return dbg.nospace() << QString(QLatin1String("UserHandle(%1)")).arg(int(type)).toLatin1().constData();
     }
 }