netfilter: x_tables: fix pointer leaks to userspace

Several netfilter matches and targets put kernel pointers into
info objects, but don't set usersize in descriptors.
This leads to kernel pointer leaks if a match/target is set
and then read back to userspace.

Properly set usersize for these matches/targets.

Found with manual code inspection.

Fixes: ec231890 ("xtables: extend matches and targets with .usersize")
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>