[PATCH v1] rust: bug: fix warn_on macro build error on UML

[Miguel Ojeda]

On Sat, Aug 1, 2026 at 5:41 AM FUJITA Tomonori <tomo at flapping.org> wrote:
>
> Use the free function `as_char_ptr_in_const_context()` instead, as other exported macros already do.

I reproduced this and the fix works -- thanks Tomonori!

Do we need to use the free function? i.e. this is not a const context,
so should we do e.g.

    $crate::str::CStrExt::as_char_ptr

?

Also:

Cc: stable at vger.kernel.org

And Cc'ing David for UML in case he is interested.

Cheers,
Miguel