netfilter: add __exit mark to helper modules

There are no __exit mark in the helper modules.
because these exit functions used to be called by init function
but now that is not. so we can add __exit mark.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
5 files changed