ivi-shell: fix destroying view that are not in a layer view list

Both the core in weston_compositor_build_view_list() with view.link and the ivi-shell in commit_screen_list() with view.layer_link don't remove the old views from the list. As a result, all views that are not currently in the list have old broken links. Destroying such a view tries to remove the view from these lists and will access the old, invalid pointers.

To avoid this, clear the list links for such views before the view is actually destroyed.

Signed-off-by: Michael Olbrich m.olbrich@pengutronix.de