[toolchain-utils] Fix remaining lint errors in toolchain-utils.

In addition to fixing the lint errors, this also fixes the Python
formatting issues (ran tc_pyformat on nearly all the files).

BUG=chromium:570450
TEST=Ran all crosperf & bisect tool unit tests.
     Ran afe_lock_machine.py (check machine status)
     Ran full crosperf test (octane, speedometer, BootPerf) on alex.

Change-Id: Ic86f9192801ac67769f3de30f1c5f0d203ce0831
Reviewed-on: https://chromium-review.googlesource.com/471886


Commit-Ready: Caroline Tice <cmtice@chromium.org>
Tested-by: Caroline Tice <cmtice@chromium.org>
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>