[PATCH v2] rust: kunit: use crate-level mapping for `c_void`

[Jesung Yang <y.j3ms.n@gmail.com>]

Use `kernel::ffi::c_void` instead of `core::ffi::c_void` for consistency
and to centralize abstraction.

Since `kernel::ffi::c_void` is a straightforward re-export of
`core::ffi::c_void`, both are functionally equivalent. However, using
`kernel::ffi::c_void` improves consistency across the kernel's Rust code
and provides a unified reference point in case the definition ever needs
to change, even if such a change is unlikely.

Signed-off-by: Jesung Yang <y.j3ms.n@gmail.com>
Link: https://rust-for-linux.zulipchat.com/#narrow/channel/288089/topic/x/near/520452733
---
So in sum, I believe it's reasonable to keep the diff unchanged... but
I'm happy to adjust if you'd prefer a different approach.
---
Changes in v2:
- Add "Link" tag to the related discussion on Zulip
- Reword the commit message to clarify `kernel::ffi::c_void` is a re-export
- Link to v1: https://lore.kernel.org/rust-for-linux/20250526162429.1114862-1-y.j3ms.n@gmail.com/
---
 rust/kernel/kunit.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs
index 81833a687b75..bd6fc712dd79 100644
--- a/rust/kernel/kunit.rs
+++ b/rust/kernel/kunit.rs
@@ -6,7 +6,8 @@
 //!
 //! Reference: <https://docs.kernel.org/dev-tools/kunit/index.html>
 
-use core::{ffi::c_void, fmt};
+use core::fmt;
+use kernel::ffi::c_void;
 
 /// Prints a KUnit error-level message.
 ///

base-commit: f4daa80d6be7d3c55ca72a8e560afc4e21f886aa
-- 
2.39.5