launcher: fix leak in launcher_weston_launch_connect()

Leak found running drm-smoke-test with ASan.

Do not forget to free the launcher before returning when we can't open
the launcher fd. Also, just set 'out = launcher' after all error paths,
otherwise we give the caller a stale pointer.

Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>

libweston/launcher-weston-launch.c

@@ -323,12 +323,15 @@ launcher_weston_launch_connect(struct weston_launcher **out, struct weston_compo
 		return -ENOMEM;
 
 	launcher->base.iface = &launcher_weston_launch_iface;
-	* (struct launcher_weston_launch **) out = launcher;
 	launcher->compositor = compositor;
 	launcher->drm_fd = -1;
 	launcher->deferred_deactivate = 0;
 	launcher->fd = launcher_weston_environment_get_fd("WESTON_LAUNCHER_SOCK");
-	if (launcher->fd != -1) {
+	if (launcher->fd == -1) {
+		free(launcher);
+		return -1;
+	}
+
 	launcher->tty = launcher_weston_environment_get_fd("WESTON_TTY_FD");
 	/* We don't get a chance to read out the original kb
 	 * mode for the tty, so just hard code K_UNICODE here
@@ -346,10 +349,9 @@ launcher_weston_launch_connect(struct weston_launcher **out, struct weston_compo
 		return -ENOMEM;
 	}
 
+	* (struct launcher_weston_launch **) out = launcher;
+
 	return 0;
-	} else {
-		return -1;
-	}
 }
 
 static void