Fix formatting

[hyperupcall]

Description

Commit b6f62a4 introduced some ShellCheck errors. This cleans up most of the low-hanging fruit (shell quoting, extraneous dollar sign in arithmetic context, inability to follow non-constant source, etc.). Note that there are still errors remaining, but much fewer exist after this change. Maybe I can fix the rest of the errors in another PR?

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• If my change requires a change to the documentation, I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• If I have added a new file, I also added it to clean_files.txt and formatted it using lint_clean_files.sh.
• I have added tests to cover my changes, and all the new and existing tests pass.

[akinomyoga]

This is essentially a duplicate of #2294.

[seefood]

This is essentially a duplicate of #2294.

true. Edwin, see if you can merge them and see what's left.

also, have you installed pre-commit?

[hyperupcall]

Oh oops I completely missed that! (my browser had an outdated view of the PR tab). I'll merge those changes in here once that's done

Yeah I've installed pre-commit I'm running all my changes through that before pushing

[seefood]

well, #2294 is done, please pull master and see if there's anything left?