xcb: Fix minor leaks in XSettings code

If some of the X11 requests fail, QXcbXSettings::QXcbXSettings() prints a
warning and returns. These error paths all caused memory leaks.

Change-Id: Idfecf03dd412c35552c3bbbebdda9c039aeadc13
Signed-off-by: Uli Schlachter <psychon@znc.in>
Reviewed-by: Laszlo Papp <lpapp@kde.org>
Reviewed-by: Dmitry Shachnev <mitya57@gmail.com>
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>
Fix for tst_qundostack autotest in shadow build

Added full path to src dir for testdata.

Task-number: QTBUG-32536
Change-Id: I5ef215d451a6407c277d2c98f21ffc35a8657e28
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Fix for tst_qundogroup autotest in shadow build

Added full path to src dir for testdata.

Task-number: QTBUG-32535
Change-Id: I38e96216e9a016869151adf0ae995e068b8b5354
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>