crypto: sun8i-ss - fix a NULL vs IS_ERR() check in sun8i_ss_hashkey

The crypto_alloc_shash() function never returns NULL. It returns error
pointers.

Fixes: 801b7d57 ("crypto: sun8i-ss - add hmac(sha1)")
Signed-off-by: Peng Wu <wupeng58@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c

@@ -30,8 +30,8 @@ static int sun8i_ss_hashkey(struct sun8i_ss_hash_tfm_ctx *tfmctx, const u8 *key,
 	int ret = 0;
 
 	xtfm = crypto_alloc_shash("sha1", 0, CRYPTO_ALG_NEED_FALLBACK);
-	if (!xtfm)
-		return -ENOMEM;
+	if (IS_ERR(xtfm))
+		return PTR_ERR(xtfm);
 
 	len = sizeof(*sdesc) + crypto_shash_descsize(xtfm);
 	sdesc = kmalloc(len, GFP_KERNEL);