Fix some compiler warnings

Change-Id: I1ac0cbba1b47c429a752c545b1475c8d7d23c5dd
Reviewed-by: hjk <hjk@qt.io>

src/libs/utils/filesystemmodel.cpp

@@ -167,6 +167,7 @@ private :
 
 void static doStat(QFileInfo &fi)
 {
+    Q_UNUSED(fi)
 //            driveInfo.stat();
 }
 
@@ -2341,6 +2342,7 @@ static QString volumeName(const QString &path)
     item->Release();
     return result;
 #else
+    Q_UNUSED(path)
     QTC_CHECK(false);
     return {};
 #endif // Q_OS_WIN

src/plugins/coreplugin/mainwindow.cpp

@@ -102,14 +102,6 @@ namespace Internal {
 
 enum { debugMainWindow = 0 };
 
-static bool isQtDesignStudio()
-{
-    QSettings *settings = Core::ICore::settings();
-    const QString qdsStandaloneEntry = "QML/Designer/StandAloneMode"; //entry from qml settings
-
-    return settings->value(qdsStandaloneEntry, false).toBool();
-}
-
 MainWindow::MainWindow()
     : AppMainWindow()
     , m_coreImpl(new ICore(this))

src/plugins/qmldesigner/designercore/projectstorage/projectstoragetypes.h

@@ -796,10 +796,10 @@ public:
     Imports imports;
     Types types;
     SourceIds updatedSourceIds;
+    SourceIds updatedFileStatusSourceIds;
     FileStatuses fileStatuses;
     ProjectDatas projectDatas;
     SourceIds updatedProjectSourceIds;
-    SourceIds updatedFileStatusSourceIds;
 };
 
 } // namespace QmlDesigner::Storage