output-management-v1: use wlr_output.description

Unfortunately, the description isn't mutable yet for this protocol [1].

[1]: swaywm/wlr-protocols#67

types/wlr_output_management_v1.c

@@ -752,11 +752,8 @@ static void manager_send_head(struct wlr_output_manager_v1 *manager,
 	zwlr_output_manager_v1_send_head(manager_resource, head_resource);
 
 	zwlr_output_head_v1_send_name(head_resource, output->name);
-
-	char description[128];
-	snprintf(description, sizeof(description), "%s %s %s (%s)",
-		output->make, output->model, output->serial, output->name);
-	zwlr_output_head_v1_send_description(head_resource, description);
+	zwlr_output_head_v1_send_description(head_resource,
+		output->description ? output->description : "Unknown");
 
 	if (output->phys_width > 0 && output->phys_height > 0) {
 		zwlr_output_head_v1_send_physical_size(head_resource,