Move the keybinding argument to a union to prevent warnings where

sizeof(int) != sizeof(void *). This has been annoying me for ages.

ok okan@, todd@

xevents.c

@@ -294,7 +294,7 @@ xev_handle_keypress(struct xevent *xev, XEvent *ee)
 		if (kb->flags & KBFLAG_NEEDCLIENT)
 			goto out;
 
-	(*kb->callback)(cc, kb->argument);
+	(*kb->callback)(cc, &kb->argument);
 
 out:
 	xev_register(xev);