tools/rtla: Add test engine support for unexpected output

Add a check() parameter to indicate which text must not appear in the
output.

Simplify the code so that we can print failures as they happen rather
than trying to figure out what went wrong after printing "not ok".  This
also means that "not ok" gets printed after the info rather than before,
which seems more intuitive anyway.

Cc: John Kacur <jkacur@redhat.com>
Cc: Costa Shulyupin <costa.shul@redhat.com>
Link: https://lore.kernel.org/20250907022325.243930-7-crwood@redhat.com


Reviewed-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Crystal Wood <crwood@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>