net: korina: handle clk prepare error in korina_probe()

in korina_probe(), the return value of clk_prepare_enable()
should be checked since it might fail. we can use
devm_clk_get_optional_enabled() instead of devm_clk_get_optional()
and clk_prepare_enable() to automatically handle the error.

Fixes: e4cd854e ("net: korina: Get mdio input clock via common clock framework")
Signed-off-by: Yuanjun Gong <ruc_gongyuanjun@163.com>
Link: https://lore.kernel.org/r/20230731090535.21416-1-ruc_gongyuanjun@163.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/korina.c

@@ -1302,11 +1302,10 @@ static int korina_probe(struct platform_device *pdev)
 	else if (of_get_ethdev_address(pdev->dev.of_node, dev) < 0)
 		eth_hw_addr_random(dev);
 
-	clk = devm_clk_get_optional(&pdev->dev, "mdioclk");
+	clk = devm_clk_get_optional_enabled(&pdev->dev, "mdioclk");
 	if (IS_ERR(clk))
 		return PTR_ERR(clk);
 	if (clk) {
-		clk_prepare_enable(clk);
 		lp->mii_clock_freq = clk_get_rate(clk);
 	} else {
 		lp->mii_clock_freq = 200000000; /* max possible input clk */