Properly initialize max size in memory usage model

Change-Id: Id77917c92191d3970727be0b360abefc87254c5b
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>

plugins/qmlprofilerextension/memoryusagemodel.cpp

@@ -44,6 +44,8 @@ MemoryUsageModel::MemoryUsageModel(QObject *parent)
                             tr(QmlProfilerModelManager::featureName(QmlDebug::ProfileMemory)),
                             QmlDebug::MemoryAllocation, QmlDebug::MaximumRangeType, parent)
 {
+    Q_D(MemoryUsageModel);
+    d->maxSize = 1;
 }
 
 quint64 MemoryUsageModel::features() const