CVE-2024-35962 netfilter: complete validation of user input

In the Linux kernel, the following vulnerability has been resolved:

netfilter: complete validation of user input

In my recent commit, I missed that do_replace() handlers
use copy_from_sockptr() (which I fixed), followed
by unsafe copy_from_sockptr_offset() calls.

In all functions, we can perform the @optlen validation
before even calling xt_alloc_table_info() with the following
check:

if ((u64)optlen < (u64)tmp.size + sizeof(tmp))
return -EINVAL;