window.c: Create xdg_surface up front

Fixes initial fullscreen for calibrator.

https://bugs.freedesktop.org/show_bug.cgi?id=76970
diff --git a/clients/terminal.c b/clients/terminal.c
index 61ea9ae..beec877 100644
--- a/clients/terminal.c
+++ b/clients/terminal.c
@@ -2963,8 +2963,9 @@
 	display_watch_fd(terminal->display, terminal->master,
 			 EPOLLIN | EPOLLHUP, &terminal->io_task);
 
-	window_set_fullscreen(terminal->window, option_fullscreen);
-	if (!window_is_fullscreen(terminal->window))
+	if (option_fullscreen)
+		window_set_fullscreen(terminal->window, 1);
+	else
 		terminal_resize(terminal, 80, 24);
 
 	return 0;