Merge branch 'ns-plugin-fixes'

Merge branch 'ns-plugin-fixes'

Vlad Buslov says:

====================
Fix problems with using ns plugin

Recent changes to plugin architecture broke some of the tests when running tdc
without specifying a test group. Fix tests incompatible with ns plugin and
modify tests to not reuse interface name of ns veth interface for dummy
interface.
====================

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