id: fix selinux/smack platform guards for non-Linux platforms

[naoNao89]

Fixes pre-commit hook failures on non-Linux platforms by adding proper #[cfg(target_os = "linux")] guards to selinux/smack feature gates.

The uucore crate only exposes these modules on Linux/Android, so the caller must match those platform restrictions.

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/date/date-locale-hour. tests/date/date-locale-hour is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/date/resolution. tests/date/resolution is passing on 'main'. Maybe you have to rebase?
Skip an intermittent issue tests/tail/symlink (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/pr/bounded-memory (passes in this run but fails in the 'main' branch)
Note: The gnu test tests/basenc/bounded-memory is now being skipped but was previously passing.
Congrats! The gnu test tests/dd/no-allocate is now passing!
Congrats! The gnu test tests/seq/seq-epipe is now passing!

[xtqqczze]

Note: I have a draft PR that would apply this more generally by defining a cfg alias:

selinux: { all(feature = "feat_selinux", any(target_os = "android", target_os = "linux"))

see #10444

[naoNao89]

tkss

[xtqqczze]

That's not to say this isn't worth considering on its own. Anyway, since you've closed this I will try get #10444 ready for review.

[naoNao89]

heh, I thought your PR covered this, so I closed my PR :v

[xtqqczze]

Ok, can you open an issue for the failures so I can fix it with my PR?

Actually, my PR doesn't cover this...

[xtqqczze]

I've added fixes for selinux/smack feature gates to #10444

[naoNao89]

tkss