entrypoint.bash is non-compliant with Shell Style Guide

[andrewpollock]

I was reviewing google/osv.dev#1017 which has a straight copy of entrypoint.bash from this repo, and it's not particularly compliant (or internally consistent) with https://google.github.io/styleguide/shellguide.html (see some of my comments on that PR).

You might like to do something about that.