Fix incorrect geometry updates in KItemListContainer

When resizing the window and when KItemListContainer::updateGeometries
is called before the scrollbar visibility is updated, a relayout is
triggered in `m_controller->view()->setGeometry` which updates the
scrollbar visibility and calls back to
`KItemListContainer::updateGeometries` again. Since the first call,
which has the wrong geometry (due to the incorrect scrollbar states),
updates the geometries of the scene and viewport after the second call
(which has the right geometry!!) returns, the final result is a size
that corresponded to the old scrollbar state before this commit.

This patch uses the new geometry of the view after updating it (since
it might not be the size we put in) and therefore makes the sizes
consistent.

BUG: 327709
FIXED-IN: 4.11.4
REVIEW: 113939