crypto: ux500 - Fix error return code in hash_hw_final()

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: 8a63b199 ("crypto: ux500 - Add driver for HASH hardware")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/ux500/hash/hash_core.c

@@ -1011,6 +1011,7 @@ static int hash_hw_final(struct ahash_request *req)
 			goto out;
 		}
 	} else if (req->nbytes == 0 && ctx->keylen > 0) {
+		ret = -EPERM;
 		dev_err(device_data->dev, "%s: Empty message with keylength > 0, NOT supported\n",
 			__func__);
 		goto out;