[otbn] Trim trailing newlines from ISS output in model
[otbn] Trim trailing newlines from ISS output in model

This makes them a bit easier to consume for the trace checker.

Signed-off-by: Rupert Swarbrick <290093e2ad2515ed2f14d749293c8cf8e02ca274@lowrisc.org>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan