Vcs: Use FilePath for working directory in DiffEditorController

Change-Id: I7b5e1349bc679bd90b7781fbe0b40485ec653473
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/plugins/diffeditor/diffutils.h

@@ -27,8 +27,10 @@
 
 #include "diffeditor_global.h"
 
-#include <QString>
+#include <utils/filepath.h>
+
 #include <QMap>
+#include <QString>
 
 QT_BEGIN_NAMESPACE
 class QFutureInterfaceBase;