Take about 1.5 sec off z_steinert_signal_integrity.pm.

Most of these fixes are merely reducing timeouts once an expected
condition is met.  The long wait-for-failure timeout isn't as
important once a test has passed, but turning off the timer entirely
isn't good either.  There could be spurious events that we don't want,
and waiting a little extra time gives us some confidence they aren't
happening.