rwho01: fix mistakes

1) fix the way it checks whether rwhod is running
2) fix the way it checks whether rwhod is started on remote host
3) fix do_cleanup
4) call do_cleanup() after do_test()
5) shorten sleep time to 5 seconds as 20 seconds are not necessary

Signed-off-by: Simon Xu <xu.simon@oracle.com>
Tested-by: Jan Stancek <jstancek@redhat.com>