downstream: ivi-shell: fix the layout-layer clearing in commit_list_screen()

downstream: ivi-shell: fix the layout-layer clearing in commit_list_screen()

	The original implementation initialized the list-head of
	the layer's view_list and re-built the list by adding
	the views of the visible surfaces to the list. This left
	the layer_link of non-visible views to point to their
	neighbours in the previous arrangement. This was no problem
	as long as those views were not unmapped or destructed,
	eg. a non-visible surface was removed.

	The fixed version goes through on the list and initializes
	the layer_link's making view destructions and unmappings safe.

Change-Id: I93b1398064228b5189782ac9030ff9515abd5283
Signed-off-by: Janos Kovacs <jankovac503@gmail.com>