tst_QCompleter::QTBUG_14292_filesystem() remove setActiveWindow()

2f6fe3a268 has made calls to
QApplicationPrivate::setActiveWindow() redundant.

Remove redundant calls from the end of the function.

Task-number: QTBUG-121488
Change-Id: I465558f404b5bf656f5ed9c3f4b2ed605da6c6b8
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>

tests/auto/widgets/util/qcompleter/tst_qcompleter.cpp

@@ -1706,7 +1706,6 @@ void tst_QCompleter::QTBUG_14292_filesystem()
     QWidget w;
     w.move(400, 200);
     w.show();
-    QApplicationPrivate::setActiveWindow(&w);
     QVERIFY(QTest::qWaitForWindowActive(&w));
     QVERIFY(!edit.hasFocus() && !comp.popup()->hasFocus());