net: ethernet: mtk-star-emac: disable napi when connect and start PHY failed in mtk_star_enable()

When failed to connect to and start PHY in mtk_star_enable() for opening
device, napi isn't disabled. When open mtk star device next time, it will
reports a invalid opcode issue. Fix it. Only be compiled, not be tested.

Fixes: 8c7bd5a4 ("net: ethernet: mtk-star-emac: new driver")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20221107012159.211387-1-shaozhengchao@huawei.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/mediatek/mtk_star_emac.c

@@ -1026,6 +1026,8 @@ static int mtk_star_enable(struct net_device *ndev)
 	return 0;
 
 err_free_irq:
+	napi_disable(&priv->rx_napi);
+	napi_disable(&priv->tx_napi);
 	free_irq(ndev->irq, ndev);
 err_free_skbs:
 	mtk_star_free_rx_skbs(priv);