tests: add destroy listener in ivi-layout test plugin

Fixes ASan reported leak:

Direct leak of 136 byte(s) in 1 object(s) allocated from:
    #0 0x7ff60173c518 in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0xe9518)
    #1 0x7ff5fcfed3fa in zalloc ../../git/weston/include/libweston/zalloc.h:38
    #2 0x7ff5fcfed8bf in wet_module_init ../../git/weston/tests/ivi-layout-test-plugin.c:196
    #3 0x7ff60161bd81 in wet_load_module ../../git/weston/compositor/main.c:941
    #4 0x7ff60161c165 in load_modules ../../git/weston/compositor/main.c:1012
    #5 0x7ff60162ced9 in wet_main ../../git/weston/compositor/main.c:3441
    #6 0x559a98fd7d4c in execute_compositor ../../git/weston/tests/weston-test-fixture-compositor.c:432
    #7 0x559a98fdb780 in weston_test_harness_execute_as_client ../../git/weston/tests/weston-test-runner.c:528
    #8 0x559a98fcbc48 in fixture_setup ../../git/weston/tests/ivi-layout-test-client.c:48
    #9 0x559a98fcbcca in fixture_setup_run_ ../../git/weston/tests/ivi-layout-test-client.c:50
    #10 0x559a98fdbd35 in main ../../git/weston/tests/weston-test-runner.c:661
    #11 0x7ff60129109a in __libc_start_main ../csu/libc-start.c:308
    #12 0x559a98fcb769 in _start (/home/pq/build/weston-meson/tests/test-ivi-layout-client+0xd769)

This also plugs the leak on wl_global_create() error path, though it
cannot really be tested.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>

tests/ivi-layout-test-plugin.c

@@ -90,6 +90,7 @@ struct test_context {
 
 struct test_launcher {
 	struct weston_compositor *compositor;
+	struct wl_listener destroy_listener;
 	struct test_context context;
 	const struct ivi_layout_interface *layout_interface;
 };
@@ -179,6 +180,16 @@ bind_runner(struct wl_client *client, void *data,
 	}
 }
 
+static void
+test_launcher_destroy(struct wl_listener *l, void *data)
+{
+	struct test_launcher *launcher;
+
+	launcher = wl_container_of(l, launcher, destroy_listener);
+
+	free(launcher);
+}
+
 WL_EXPORT int
 wet_module_init(struct weston_compositor *compositor,
 		       int *argc, char *argv[])
@@ -200,10 +211,20 @@ wet_module_init(struct weston_compositor *compositor,
 	launcher->compositor = compositor;
 	launcher->layout_interface = iface;
 
+	if (!weston_compositor_add_destroy_listener_once(compositor,
+							 &launcher->destroy_listener,
+							 test_launcher_destroy)) {
+		free(launcher);
+		return -1;
+	}
+
 	if (wl_global_create(compositor->wl_display,
 			     &weston_test_runner_interface, 1,
-			     launcher, bind_runner) == NULL)
+			     launcher, bind_runner) == NULL) {
+		wl_list_remove(&launcher->destroy_listener.link);
+		free(launcher);
 		return -1;
+	}
 
 	return 0;
 }