run go fmt, add .lbox.check

There were a couple of files that were changed by
running "go fmt", and I noticed there wasn't a
.lbox.check file. I'm guessing goyaml predated
the functionality in lbox. So I ran the tool,
and added the check file. No functional changes.

R=niemeyer
CC=
https://codereview.appspot.com/7801047