Merge branch 'Fixes-for-running-mirror-to-gretap-tests-on-veth'

Petr Machata says:

====================
Fixes for running mirror-to-gretap tests on veth

The forwarding selftests infrastructure makes it possible to run the
individual tests on a purely software netdevices. Names of interfaces to
run the test with can be passed as command line arguments to a test.
lib.sh then creates veth pairs backing the interfaces if none exist in
the system.

However, the tests need to recognize that they might be run on a soft
device. Many mirror-to-gretap tests are buggy in this regard. This patch
set aims to fix the problems in running mirror-to-gretap tests on veth
devices.

In patch #1, a service function is split out of setup_wait().
In patch #2, installing a trap is made optional.
In patch #3, tc filters in several tests are tweaked to work with veth.
In patch #4, the logic for waiting for neighbor is fixed for veth.
====================

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