hwrng: st - Fix missing clk_disable_unprepare() on error in st_rng_probe()

Fix the missing clk_disable_unprepare() before return
from st_rng_probe() in the error handling case.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Acked-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/st-rng.c

@@ -108,6 +108,7 @@ static int st_rng_probe(struct platform_device *pdev)
 	ret = hwrng_register(&ddata->ops);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to register HW RNG\n");
+		clk_disable_unprepare(clk);
 		return ret;
 	}