rustdoc: fix broken intra doc links

[cakebaker]

This PR fixes some broken intra doc links. It should fix the following error shown by the CICD / Documentation/warnings job in the CI (see, for example, https://github.com/uutils/coreutils/actions/runs/18963810909/job/54156487338?pr=9094):

error: unresolved link to `Some(bytes)`
   --> src/uu/tail/src/chunks.rs:211:53
    |
211 |     /// [`UResult<None>`] or else the result with [`Some(bytes)`] where bytes is the number of bytes
    |                                                     ^^^^^^^^^^^ no item named `Some(bytes)` in scope
   |
    = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
    = note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(rustdoc::broken_intra_doc_links)]`

[codspeed-hq]

CodSpeed Performance Report

Merging #9097 will degrade performances by 31.87%

_{Comparing cakebaker:rustdoc_fix_link (6cb815e) with main (95b266f)}

Summary

⚡ 16 improvements
❌ 16 regressions
✅ 93 untouched

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
❌	cp_large_file[16]	297.9 µs	339 µs	-12.12%
❌	cp_recursive_deep_tree[(120, 4)]	13.3 ms	13.6 ms	-2.77%
❌	du_deep_tree[(100, 3)]	1.1 ms	1.2 ms	-2.61%
❌	expand_custom_tabstops[50000]	25.9 ms	36.6 ms	-29.13%
❌	expand_many_lines[100000]	100.9 ms	148.1 ms	-31.87%
⚡	fold_custom_width[50000]	46.6 ms	43.4 ms	+7.54%
⚡	fold_many_lines[100000]	125.4 ms	116.2 ms	+7.83%
❌	ls_recursive_deep_tree[(200, 2)]	2.1 ms	2.2 ms	-2.38%
⚡	ls_recursive_long_all_balanced_tree[(6, 4, 15)]	139.8 ms	136.1 ms	+2.69%
⚡	ls_recursive_long_all_mixed_tree	4 ms	2.8 ms	+42.65%
⚡	ls_recursive_long_all_wide_tree[(15000, 1500)]	148.7 ms	142.5 ms	+4.37%
❌	ls_recursive_mixed_tree	1.4 ms	1.4 ms	-3.93%
❌	ls_recursive_wide_tree[(10000, 1000)]	51.4 ms	53 ms	-3.16%
❌	mv_directory	3.1 ms	3.5 ms	-9.86%
❌	mv_force_overwrite	121.8 ms	124.9 ms	-2.46%
⚡	numfmt_large_numbers_si[10000]	34.5 ms	32.9 ms	+4.66%
❌	numfmt_round_modes[("up", 10000)]	32.8 ms	34.7 ms	-5.54%
⚡	seq_formatted	99.7 ms	97.2 ms	+2.51%
⚡	seq_integers	26.7 ms	26.1 ms	+2.15%
⚡	seq_with_step	13.6 ms	13.3 ms	+2.12%
...	...	...	...	...

ℹ️ Only the first 20 benchmarks are displayed. Go to the app to view all benchmarks.

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/misc/tee (passes in this run but fails in the 'main' branch)