crypto: s5p-sss - use crypto_shash_tfm_digest()

Instead of manually allocating a 'struct shash_desc' on the stack and
calling crypto_shash_digest(), switch to using the new helper function
crypto_shash_tfm_digest() which does this for us.

Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Vladimir Zapolskiy <vz@mleia.com>
Cc: Kamil Konieczny <k.konieczny@samsung.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/s5p-sss.c

@@ -1520,37 +1520,6 @@ static int s5p_hash_update(struct ahash_request *req)
 	return s5p_hash_enqueue(req, true); /* HASH_OP_UPDATE */
 }
 
-/**
- * s5p_hash_shash_digest() - calculate shash digest
- * @tfm:	crypto transformation
- * @flags:	tfm flags
- * @data:	input data
- * @len:	length of data
- * @out:	output buffer
- */
-static int s5p_hash_shash_digest(struct crypto_shash *tfm, u32 flags,
-				 const u8 *data, unsigned int len, u8 *out)
-{
-	SHASH_DESC_ON_STACK(shash, tfm);
-
-	shash->tfm = tfm;
-
-	return crypto_shash_digest(shash, data, len, out);
-}
-
-/**
- * s5p_hash_final_shash() - calculate shash digest
- * @req:	AHASH request
- */
-static int s5p_hash_final_shash(struct ahash_request *req)
-{
-	struct s5p_hash_ctx *tctx = crypto_tfm_ctx(req->base.tfm);
-	struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
-
-	return s5p_hash_shash_digest(tctx->fallback, req->base.flags,
-				     ctx->buffer, ctx->bufcnt, req->result);
-}
-
 /**
  * s5p_hash_final() - close up hash and calculate digest
  * @req:	AHASH request
@@ -1582,8 +1551,12 @@ static int s5p_hash_final(struct ahash_request *req)
 	if (ctx->error)
 		return -EINVAL; /* uncompleted hash is not needed */
 
-	if (!ctx->digcnt && ctx->bufcnt < BUFLEN)
-		return s5p_hash_final_shash(req);
+	if (!ctx->digcnt && ctx->bufcnt < BUFLEN) {
+		struct s5p_hash_ctx *tctx = crypto_tfm_ctx(req->base.tfm);
+
+		return crypto_shash_tfm_digest(tctx->fallback, ctx->buffer,
+					       ctx->bufcnt, req->result);
+	}
 
 	return s5p_hash_enqueue(req, false); /* HASH_OP_FINAL */
 }