net: systemport: free dev before on error path

On the error path, it should goto the error handling label to free
allocated memory rather than directly return.

Fixes: 31bc72d9 ("net: systemport: fetch and use clock resources")
Signed-off-by: Pan Bian <bianpan2016@163.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210120044423.1704-1-bianpan2016@163.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/bcmsysport.c

@@ -2503,8 +2503,10 @@ static int bcm_sysport_probe(struct platform_device *pdev)
 	priv = netdev_priv(dev);
 
 	priv->clk = devm_clk_get_optional(&pdev->dev, "sw_sysport");
-	if (IS_ERR(priv->clk))
-		return PTR_ERR(priv->clk);
+	if (IS_ERR(priv->clk)) {
+		ret = PTR_ERR(priv->clk);
+		goto err_free_netdev;
+	}
 
 	/* Allocate number of TX rings */
 	priv->tx_rings = devm_kcalloc(&pdev->dev, txq,