ivi-shell: don't check layer is already on the screen

If a layer is removed from a screen's render order list, but the
changes are not commited. Then, the layer could not be added to the
same screen. Because on_screen property of the layer is only changed
in ivi_layout_commit_changes API, when active render order of the screen
is changed.

It is not possible to change the order of layers in a screen without
clearing and commiting the changes before. This patch fixes this issue.

After this patch, the pending render order list of a screen is always
modified regardless of its active render order list.

Signed-off-by: Emre Ucan <eucan@de.adit-jv.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

ivi-shell/ivi-layout.c

@@ -1646,11 +1646,6 @@ ivi_layout_screen_add_layer(struct weston_output *output,
 
 	iviscrn = get_screen_from_output(output);
 
-	if (addlayer->on_screen == iviscrn) {
-		weston_log("ivi_layout_screen_add_layer: addlayer is already available\n");
-		return IVI_SUCCEEDED;
-	}
-
 	wl_list_remove(&addlayer->pending.link);
 	wl_list_insert(&iviscrn->pending.layer_list, &addlayer->pending.link);