hwrng: ingenic - Fix a resource leak in an error handling path

In case of error, we should call 'clk_disable_unprepare()' to undo a
previous 'clk_prepare_enable()' call, as already done in the remove
function.

Fixes: 406346d2 ("hwrng: ingenic - Add hardware TRNG for Ingenic X1830")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Tested-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/ingenic-trng.c

@@ -113,13 +113,17 @@ static int ingenic_trng_probe(struct platform_device *pdev)
 	ret = hwrng_register(&trng->rng);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to register hwrng\n");
-		return ret;
+		goto err_unprepare_clk;
 	}
 
 	platform_set_drvdata(pdev, trng);
 
 	dev_info(&pdev->dev, "Ingenic DTRNG driver registered\n");
 	return 0;
+
+err_unprepare_clk:
+	clk_disable_unprepare(trng->clk);
+	return ret;
 }
 
 static int ingenic_trng_remove(struct platform_device *pdev)