amd-xgbe: Fix error return code in xgbe_probe()

Fix to return a negative error code from the setting real tx queue
count error handling case instead of 0.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: NTom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/amd/xgbe/xgbe-main.c

@@ -339,7 +339,8 @@ static int xgbe_probe(struct platform_device *pdev)
 	/* Calculate the number of Tx and Rx rings to be created */
 	pdata->tx_ring_count = min_t(unsigned int, num_online_cpus(),
 				     pdata->hw_feat.tx_ch_cnt);
-	if (netif_set_real_num_tx_queues(netdev, pdata->tx_ring_count)) {
+	ret = netif_set_real_num_tx_queues(netdev, pdata->tx_ring_count);
+	if (ret) {
 		dev_err(dev, "error setting real tx queue count\n");
 		goto err_io;
 	}