net: stmmac: dwmac-intel-plat: fix error return code in intel_eth_plat_probe()

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: 9efc9b2 ("net: stmmac: Add dwmac-intel-plat for GBE driver")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Link: https://lore.kernel.org/r/1605249243-17262-1-git-send-email-zhangchangzhong@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Zhang Changzhong

drivers/net/ethernet/stmicro/stmmac/dwmac-intel-plat.c

@@ -113,8 +113,10 @@ static int intel_eth_plat_probe(struct platform_device *pdev)
 		/* Enable TX clock */
 		if (dwmac->data->tx_clk_en) {
 			dwmac->tx_clk = devm_clk_get(&pdev->dev, "tx_clk");
-			if (IS_ERR(dwmac->tx_clk))
+			if (IS_ERR(dwmac->tx_clk)) {
+				ret = PTR_ERR(dwmac->tx_clk);
 				goto err_remove_config_dt;
+			}
 
 			clk_prepare_enable(dwmac->tx_clk);