hwrng: core - remove redundant initialization of variable err

'err' will be assigned later and cleanup the redundant initialization.

Cc: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NShaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/core.c

@@ -323,7 +323,7 @@ static ssize_t hwrng_attr_current_store(struct device *dev,
 					struct device_attribute *attr,
 					const char *buf, size_t len)
 {
-	int err = -ENODEV;
+	int err;
 	struct hwrng *rng, *old_rng, *new_rng;
 
 	err = mutex_lock_interruptible(&rng_mutex);