crypto_hash_walk_first
hwh->walkbytes = crypto_hash_walk_first(req, &hwh->walk);
EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
nbytes = crypto_hash_walk_first(req, &walk);
int crypto_hash_walk_first(struct ahash_request *req,