ieee802154/atusb: Set default ed level to 0xbe like the rest of these drivers

Signed-off-by: NStefan Schmidt <stefan@osg.samsung.com>
Acked-by: NAlexander Aring <alex.aring@gmail.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

drivers/net/ieee802154/atusb.c

@@ -365,8 +365,8 @@ static int atusb_channel(struct ieee802154_hw *hw, u8 page, u8 channel)
 
 static int atusb_ed(struct ieee802154_hw *hw, u8 *level)
 {
-	/* @@@ not used by the stack yet */
-	*level = 0;
+	BUG_ON(!level);
+	*level = 0xbe;
 	return 0;
 }