swaynag: fix pointer button events on scaled outputs

sway#6504 simplified rendering code by setting scaling at cairo, but
that also changed button position records into ones without scale
multiplication, breaking button events. This fixes it by not multiplying
scale on events handling as well.

swaynag/swaynag.c

@@ -200,8 +200,8 @@ static void wl_pointer_button(void *data, struct wl_pointer *wl_pointer,
 		return;
 	}
 
-	double x = seat->pointer.x * swaynag->scale;
+	double x = seat->pointer.x;
-	double y = seat->pointer.y * swaynag->scale;
+	double y = seat->pointer.y;
 	for (int i = 0; i < swaynag->buttons->length; i++) {
 		struct swaynag_button *nagbutton = swaynag->buttons->items[i];
 		if (x >= nagbutton->x