Symbian: Check the correct data

Make sure to check the data we are actually using later.

src/plugins/qt4projectmanager/qt-s60/s60projectchecker.cpp

@@ -47,7 +47,7 @@ QList<ProjectExplorer::Task>
 S60ProjectChecker::reportIssues(const QString &proFile, const QtVersion *version)
 {
     QList<ProjectExplorer::Task> results;
-    const QString epocRootDir = QDir(Internal::S60Manager::instance()->deviceForQtVersion(version).epocRoot).absolutePath();
+    const QString epocRootDir = version->systemRoot();
     QFileInfo cppheader(epocRootDir + QLatin1String("/epoc32/include/stdapis/string.h"));
 #if defined (Q_OS_WIN)
     // Report an error if project- and epoc directory are on different drives: