____cacheline_aligned is currently undefined, this makes this check in
ip_tables.c check_entry_size_and_hooks() fail on 64 bit because
newinfo->entries and thus e is only 4-byte aligned:

        if ((unsigned long)e % __alignof__(struct ipt_entry) != 0
            || (unsigned char *)e + sizeof(struct ipt_entry) >= limit) {
                duprintf("Bad offset %p\n", e);
                return -EINVAL;
        }

This patch makes it align to 8 byte.