tee: rename ErrorKind::Other to its usage

[oech3]

No description provided.

[sylvestre]

sorry but i don't understand the point of this PR ?!

[oech3]

I wanted to concentrate comment about hacky usage of ErrorKind::Other.

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/date/date-locale-hour (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/tail-n0f (passes in this run but fails in the 'main' branch)

[codspeed-hq]

Merging this PR will not alter performance

✅ 319 untouched benchmarks
⏩ 46 skipped benchmarks¹

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_{Comparing oech3:tee-cleanup (0206006) with main (aaf4a35)}

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. ↩

[oech3]

Would you review this? There are 3 commens describing same hacky usage of ErrorKind::Other which is verbose.