bpf: make bpf_check_uarg_tail_zero() use check_zeroed_user()

			     size_t expected_size,

			     size_t actual_size)

{

	unsigned char __user *addr;

	unsigned char __user *end;

	unsigned char val;

	int err;

	unsigned char __user *addr = uaddr + expected_size;

	int res;

	if (unlikely(actual_size > PAGE_SIZE))	/* silly large */

		return -E2BIG;

	if (unlikely(!access_ok(uaddr, actual_size)))

		return -EFAULT;

	if (actual_size <= expected_size)

		return 0;

	addr = uaddr + expected_size;

	end  = uaddr + actual_size;

	for (; addr < end; addr++) {

		err = get_user(val, addr);

		if (err)

			return err;

		if (val)

			return -E2BIG;

	}

	return 0;

	res = check_zeroed_user(addr, actual_size - expected_size);

	if (res < 0)

		return res;

	return res ? 0 : -E2BIG;

}

const struct bpf_map_ops bpf_map_offload_ops = {