chmod: modified no-op errors for parity with gnu

[max-amb]

Part of #12584, fixes chmod/only-op.sh.

[codspeed-hq]

Merging this PR will not alter performance

✅ 210 untouched benchmarks
⏩ 159 skipped benchmarks¹

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_{Comparing max-amb:chmod_no_op (9105442) with main (4223537)}

Footnotes

1. 159 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. ↩

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/cut/bounded-memory (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/date/date-locale-hour (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/misc/tty-eof (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/chmod/only-op is no longer failing!
Note: The gnu test tests/tail/tail-n0f is now being skipped but was previously passing.