[PATCH v1] um: fix incompatible argument type in iounmap()

[Miguel Ojeda]

On Wed, Apr 9, 2025 at 8:16 AM FUJITA Tomonori
<fujita.tomonori at gmail.com> wrote:
>
> Align iounmap() signature with other architectures.

Most indeed have `volatile`, but nios2 and m68k don't -- Cc'ing them
just in case.

Cc'ing also the original authors of both sides too.

Thanks!

Cheers,
Miguel