Fix pressing escape in help viewers find tool bar (in Help mode)

The tool bar should not be a direct child of the widget that is searched
(i.e. that has the FindSupport attached).

Change-Id: Ib6b17c4d2df39798086ae41d1b3a0e394e7afa75
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>