3921 fmt followups

[tankyleo]

Formatting follow-ups from #3921

[ldk-reviews-bot]

👋 Thanks for assigning @TheBlueMatt as a reviewer!
I'll wait for their review and will help manage the review process.
Once they submit their review, I'll check if a second reviewer would be helpful.

[codecov]

Codecov Report

❌ Patch coverage is 90.94077% with 26 lines in your changes missing coverage. Please review.
✅ Project coverage is 88.78%. Comparing base (d16e65d) to head (37e69db).
⚠️ Report is 8 commits behind head on main.

Files with missing lines	Patch %	Lines
lightning/src/ln/channel.rs	86.73%	26 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4031      +/-   ##
==========================================
+ Coverage   88.76%   88.78%   +0.01%     
==========================================
  Files         176      176              
  Lines      128521   128700     +179     
  Branches   128521   128700     +179     
==========================================
+ Hits       114088   114269     +181     
- Misses      11844    11854      +10     
+ Partials     2589     2577      -12     

Flag	Coverage Δ
fuzzing	21.96% <54.35%> (+0.09%)	⬆️
tests	88.61% <90.94%> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[TheBlueMatt]

Thanks

[ldk-reviews-bot]

👋 The first review has been submitted!

Do you think this PR is ready for a second reviewer? If so, click here to assign a second reviewer.