crypto: caam - Use kmalloc_array() in ahash_setkey()

* A multiplication for the size determination of a memory allocation
  indicated that an array data structure should be processed.
  Thus use the corresponding function "kmalloc_array".

  This issue was detected by using the Coccinelle software.

* Replace the specification of a data type by a pointer dereference
  to make the corresponding size determination a bit safer according to
  the Linux coding style convention.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/caam/caamhash.c

@@ -525,8 +525,9 @@ static int ahash_setkey(struct crypto_ahash *ahash,
 #endif
 
 	if (keylen > blocksize) {
-		hashed_key = kmalloc(sizeof(u8) * digestsize, GFP_KERNEL |
-				     GFP_DMA);
+		hashed_key = kmalloc_array(digestsize,
+					   sizeof(*hashed_key),
+					   GFP_KERNEL | GFP_DMA);
 		if (!hashed_key)
 			return -ENOMEM;
 		ret = hash_digest_key(ctx, key, &keylen, hashed_key,