clippy: fix warnings

[cakebaker]

This PR fixes clippy warnings from the question_mark, for_kv_map, and useless_borrows_in_formatting lints that are shown with Rust 1.97.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 19.19%. Comparing base (ebd7d9b) to head (fb25d4b).
⚠️ Report is 26 commits behind head on main.

Files with missing lines	Patch %	Lines
src/uu/pgrep/src/process.rs	0.00%	2 Missing ⚠️
src/uu/top/src/header.rs	0.00%	1 Missing ⚠️
src/uu/top/src/tui/mod.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #736   +/-   ##
=======================================
  Coverage   19.19%   19.19%           
=======================================
  Files          68       68           
  Lines       10158    10157    -1     
  Branches      546      546           
=======================================
  Hits         1950     1950           
+ Misses       8208     8207    -1     

Flag	Coverage Δ
macos_latest	6.74% <0.00%> (ø)
ubuntu_latest	19.55% <0.00%> (+<0.01%)	⬆️
windows_latest	0.02% <0.00%> (ø)

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[cakebaker]

I merged this PR myself to get the CI back to green.