at86rf230: remove unnecessary print of async error

The async error function will already printout the errno over dev_err.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/net/ieee802154/at86rf230.c

@@ -664,7 +664,6 @@ at86rf230_async_state_change_start(void *context)
 			enable_irq(lp->spi->irq);
 
 		at86rf230_async_error(lp, &lp->state, rc);
-		dev_err(&lp->spi->dev, "spi_async error %d\n", rc);
 	}
 }