Remove non-functional tracking of profiler root's vertical scroll

Vertical scrolling doesn't work at the moment and has to be implemented
in a different way. Besides, the code tracking the root's vertical
scroll hasn't done anything useful in a long time.

Change-Id: If2add3874cba971bbaace2c22fbf1b2bf0b463b7
Reviewed-by: Kai Koehne <kai.koehne@digia.com>
Reviewed-by: Ulf Hermann <ulf.hermann@digia.com>