Merge branch 'selftests-updates-for-mlxsw-driver-test'

Jiri Pirko says:

====================
selftests: updates for mlxsw driver test

This patchset contains tweaks to the existing tests and is also adding
couple of new ones, namely tests for shared buffer and red offload.
====================

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