hwrng: stm32 - add missing clk_disable_unprepare() in stm32_rng_init()

Add clk_disable_unprepare() in the error path in stm32_rng_init().

Fixes: 6b85a7e141 ("hwrng: stm32 - implement STM32MP13x support")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/stm32-rng.c

@@ -325,6 +325,7 @@ static int stm32_rng_init(struct hwrng *rng)
 							(!(reg & RNG_CR_CONDRST)),
 							10, 50000);
 		if (err) {
+			clk_disable_unprepare(priv->clk);
 			dev_err((struct device *)priv->rng.priv,
 				"%s: timeout %x!\n", __func__, reg);
 			return -EINVAL;