Don't match input interface in POSTROUTING table
Don't match input interface in POSTROUTING table

Netfilter postrouting hooks don't provide the input interface. That
works fine in iptables implementation as the comparison simply happens
against an empty string, but cause problems with nftables which
aborts rule processing due to no data to compare against and
the rule doesn't match.
This is a problem in systems where nftables are used (e.g. RHEL 8).

This patch fixes this issue by removing input interface from
POSTROUTING rule used to prevent SNAT for router's internal traffic.

Change-Id: I79bb8054c113c77e7c96d64ec1408236d24b23b6
Closes-Bug: #1834825

openstack/neutron,mahak/neutron,openstack/neutron,openstack/neutron,mahak/neutron,mahak/neutron