input/trace32_ad: silence format match logging, improve robustness

input/trace32_ad: silence format match logging, improve robustness

There is not much point in log messages about format mismatch in the
auto detect phase, where each module gets queried in turn and most are
supposed to not match.

Do not print non-printable characters in log messages. Those could occur
in the format detection phase, or in the regular processing of input
files that either are unexpected or invalid (or is there a binary header
format variant even?).