simplify many match

[oech3]

No description provided.

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/date/date-locale-hour (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/tail/tail-n0f (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/tail/symlink (passes in this run but fails in the 'main' branch)
Note: The gnu test tests/seq/seq-epipe is now being skipped but was previously passing.
Note: The gnu test tests/misc/write-errors was skipped on 'main' but is now failing.

[xtqqczze]

I prefer let-else over map_err with an intentional ignore:

Suggested change

	parse_gid_from_str(from_group)
	.map(IfFrom::Group)
	.map_err(|_| {
	USimpleError::new(
	1,
	translate!("chgrp-error-invalid-user", "from_group" => from_group),
	));
	}
	}
	)
	})?
	let Ok(g) = parse_gid_from_str(from_group) else {
	return Err(USimpleError::new(
	1,
	translate!("chgrp-error-invalid-user", "from_group" => from_group),
	));
	};
	IfFrom::Group(g)

In this case, the if could also be collapsed into a let-chain.

[Devel08]

thiserror could be used for that too, something like #13620

[codspeed-hq]

Merging this PR will degrade performance by 3.39%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

❌ 1 regressed benchmark
✅ 346 untouched benchmarks
⏩ 46 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	numfmt_to_si_precision[10000]	90.6 ms	93.8 ms	-3.39%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing oech3:fmt-ret-err (548f9a2) with main (5d75e5e)}

Footnotes

1. 46 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[sylvestre]

Please ping me when it is ready

[oech3]

Please ping me when it is ready

ready (CI is passing).

[xtqqczze]

Conflicts with #13620.