desktop-shell: fix the unlock dialog decorations

The decorations were not responding, could not move or resize the
dialog, and it painted with a black shade.

When the dialog is created, schedule a resize instead of a repaint. The
resize will initialise the widget tree, and let everything draw and work
as it should.

Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>
diff --git a/clients/desktop-shell.c b/clients/desktop-shell.c
index 4303ad0..e2e2433 100644
--- a/clients/desktop-shell.c
+++ b/clients/desktop-shell.c
@@ -530,7 +530,7 @@
 	desktop_shell_set_lock_surface(desktop->shell,
 	       window_get_wl_shell_surface(dialog->window));
 
-	window_schedule_redraw(dialog->window);
+	window_schedule_resize(dialog->window, 260, 230);
 
 	return dialog;
 }