We are going to use do_run_test() in multiprocessing environment, where
we'll not be able to change original runner object.

Happily, the only thing we change is that last_elapsed and it's simple
to do it in run_tests() instead. All other accesses to self in
do_runt_test() and in run_test() are read-only.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20211203122223.2780098-3-vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Tested-by: John Snow <jsnow@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>