[autotest] Usability improvements for freon_swap.
This adds a few usability conveniences to contrib/freon_swap,
based on usage experience:
* Check the command line, and report usage errors.
* Allow naming either the freon board or the non-freon board.
* Better align the error messages with balance_pool and the
web documentation for balance_pool.
BUG=None
TEST=Run the command, see the new code produce the expected output
Change-Id: I10a0b2a2dbcdbfe50d2bd54e352f3f91378e6d0c
Reviewed-on: https://chromium-review.googlesource.com/266516
Tested-by: Richard Barnette <jrbarnette@chromium.org>
Reviewed-by: Mungyung Ryu <mkryu@google.com>
Commit-Queue: Richard Barnette <jrbarnette@chromium.org>
1 file changed