selftests: openvswitch: Be more verbose with selftest debugging.

The openvswitch selftest is difficult to debug for anyone that isn't
directly familiar with the openvswitch module and the specifics of the
test cases.  Many times when something fails, the debug log will be
sparsely populated and it takes some time to understand where a failure
occured.

Increase the amount of details logged to the debug log by trapping all
'info' logs, and all 'ovs_sbx' commands.

Signed-off-by: Aaron Conole <aconole@redhat.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240702132830.213384-4-aconole@redhat.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>