Tighten up clippy

[LebedevRI]

No description provided.

[github-actions]

The proposed diff is not rustfmtted.
To make this check pass, download the following patch
(via browser, you must be logged-in in order for this URL to work),
(NOTE: save it into the repo checkout dir for the snippet to work)
https://github.com/darktable-org/rawspeed.rs/actions/runs/15937233509/artifacts/3422859902
... and run:

cd <path/to/repo/checkout> # NOTE: use your own path here
unzip rustfmt.patch.zip
git stash # Temporairly stash away any preexisting diff
git apply rustfmt.patch # Apply the diff
git add -u # Stage changed files
git commit -m "Applying rustfmt" # Commit the patch
git push
git stash pop # Unstast preexisting diff
rm rustfmt.patch.zip rustfmt.patch

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.69%. Comparing base (fb4e7e7) to head (5489cf2).
Report is 18 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #22      +/-   ##
==========================================
- Coverage   93.69%   93.69%   -0.01%     
==========================================
  Files          24       24              
  Lines        2809     2808       -1     
  Branches     2809     2808       -1     
==========================================
- Hits         2632     2631       -1     
  Misses          3        3              
  Partials      174      174              

Flag	Coverage Δ
LLVM=16	93.63% <100.00%> (-0.01%)	⬇️
LLVM=19	93.69% <100.00%> (-0.01%)	⬇️
endianness=big	93.65% <100.00%> (-0.01%)	⬇️
endianness=little	93.63% <100.00%> (-0.01%)	⬇️
host=aarch64	93.63% <100.00%> (-0.01%)	⬇️
host=x86_64	93.69% <100.00%> (-0.01%)	⬇️
linux	93.69% <100.00%> (-0.01%)	⬇️
macos	93.63% <100.00%> (-0.01%)	⬇️
profile=dev	93.69% <100.00%> (-0.01%)	⬇️
profile=release	93.69% <100.00%> (-0.01%)	⬇️
rust=nightly	93.69% <100.00%> (-0.01%)	⬇️
rust=nightly-msvc	93.63% <100.00%> (-0.01%)	⬇️
rust=stable	93.69% <100.00%> (-0.01%)	⬇️
rust=stable-msvc	93.63% <100.00%> (-0.01%)	⬇️
target=aarch64	93.63% <100.00%> (-0.01%)	⬇️
target=powerpc64	93.65% <100.00%> (-0.01%)	⬇️
target=x86_64	93.63% <100.00%> (-0.01%)	⬇️
windows	93.63% <100.00%> (-0.01%)	⬇️

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