Merge branch 'Add-selftests-for-pedit-ex-munge-ip6-dsfield'

Petr Machata says:

====================
Add selftests for pedit ex munge ip6 dsfield

Patch #1 extends the existing generic forwarding selftests to cover pedit
ex munge ip6 traffic_class as well. Patch #2 adds TDC test coverage.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>