Bootrom Tools: Automated test: Fixed error message
Bootrom Tools: Automated test: Fixed error message

When adding failure checking to haps_boot.py, I noticed that the IOError
messages were printing as None. Fixed the print method for IOError and
ValueError.

Also fixed 3 minor flake8 squawks

Testing Done: Dev. testing
Bug Number: trivial
Review URL: https://reviews.leaflabs.com/r/1480/
Reviewed by:

Signed-off-by:  Morgan Girling <980e61e2e2b82c453db57c2e8646c01fbd3318cd@bsquare.com>

gregkh/bootrom-tools,projectara/bootrom-tools,gregkh/bootrom-tools,projectara/bootrom-tools,gregkh/bootrom-tools,projectara/bootrom-tools