compositor: stop direct accessing core struct member

Commit "weston-log: add function to avoid direct
access to compositor members in non-core code" added the
function weston_compositor_add_log_scope mainly to allow
libweston users to avoid direct accessing core structs, as
weston_compositor.

Replace weston_log_context_add_log_scope usage by
weston_compositor_add_log_scope.

Signed-off-by: Leandro Ribeiro <leandrohr@riseup.net>

libweston/compositor.c

@@ -7301,17 +7301,17 @@ weston_compositor_create(struct wl_display *display,
 				  WESTON_LAYER_POSITION_CURSOR);
 
 	ec->debug_scene =
-		weston_log_ctx_add_log_scope(ec->weston_log_ctx, "scene-graph",
+		weston_compositor_add_log_scope(ec, "scene-graph",
-					     "Scene graph details\n",
+						"Scene graph details\n",
-					     debug_scene_graph_cb, NULL,
+						debug_scene_graph_cb, NULL,
-					     ec);
+						ec);
 
 	ec->timeline =
-		weston_log_ctx_add_log_scope(ec->weston_log_ctx, "timeline",
+		weston_compositor_add_log_scope(ec, "timeline",
-					     "Timeline event points\n",
+						"Timeline event points\n",
-					     weston_timeline_create_subscription,
+						weston_timeline_create_subscription,
-					     weston_timeline_destroy_subscription,
+						weston_timeline_destroy_subscription,
-					     ec);
+						ec);
 	return ec;
 
 fail: