hwrng: stm32 - put IP into RPM suspend on failure

In case of an irrecoverable failure, put the IP into RPM suspend
to avoid RPM imbalance. I did not trigger this case, but it seems
it should be done based on reading the code.

Fixes: b17bc6eb ("hwrng: stm32 - rework error handling in stm32_rng_read()")
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/stm32-rng.c

@@ -220,7 +220,8 @@ static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
 				if (err && i > RNG_NB_RECOVER_TRIES) {
 					dev_err((struct device *)priv->rng.priv,
 						"Couldn't recover from seed error\n");
-					return -ENOTRECOVERABLE;
+					retval = -ENOTRECOVERABLE;
+					goto exit_rpm;
 				}
 
 				continue;
@@ -238,7 +239,8 @@ static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
 			if (err && i > RNG_NB_RECOVER_TRIES) {
 				dev_err((struct device *)priv->rng.priv,
 					"Couldn't recover from seed error");
-				return -ENOTRECOVERABLE;
+				retval = -ENOTRECOVERABLE;
+				goto exit_rpm;
 			}
 
 			continue;
@@ -250,6 +252,7 @@ static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
 		max -= sizeof(u32);
 	}
 
+exit_rpm:
 	pm_runtime_mark_last_busy((struct device *) priv->rng.priv);
 	pm_runtime_put_sync_autosuspend((struct device *) priv->rng.priv);