Backporting "netfilter: xt_hashlimit: Fix integer divide round to zero." to stable kernels

Hi,

A customer of mine has been hitting hashlimits issues in netfilter by
switching from Debian 8 (3.16.y) to Debian 9 (4.9.y), making iptables
hashlimits unusable for production.

This issue has been fixed in mainline with this commit:
| commit ad5b55761956427f61ed9c96961bf9c5cd4f92dc
| Author: Alban Browaeys [off-list ref]
| Date:   Mon Feb 6 23:50:33 2017 +0100
| 
|     netfilter: xt_hashlimit: Fix integer divide round to zero.

Backporting this commit to Debian 9's 4.9.y kernel series has been
confirmed to fix the bug there. It might be worth considering it for
other stable kernels though.

Downstream bug reports:
  https://bugs.debian.org/872907
  https://bugs.debian.org/884983

Thanks for considering.


Cheers,
-- 
Cyril Brulebois -- Debian Consultant @ DEBAMAX -- https://debamax.com/