rust: debugfs: use `kernel::fmt`

Reduce coupling to implementation details of the formatting machinery by
avoiding direct use for `core`'s formatting traits and macros.

This backslid in commit 40ecc49466c8 ("rust: debugfs: Add support for
callback-based files") and commit 5e40b591cb46 ("rust: debugfs: Add
support for read-only files").

Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Link: https://patch.msgid.link/20251018-cstr-core-v18-7-9378a54385f8@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

1 files changed, 3 insertions, 4 deletions

diff --git a/rust/kernel/debugfs/callback_adapters.rs b/rust/kernel/debugfs/callback_adapters.rs
index 6c024230f676..a260d8dee051 100644
--- a/rust/kernel/debugfs/callback_adapters.rs
+++ b/rust/kernel/debugfs/callback_adapters.rs
@@ -5,10 +5,9 @@
 //! than a trait implementation. If provided, it will override the trait implementation.
 
 use super::{Reader, Writer};
+use crate::fmt;
 use crate::prelude::*;
 use crate::uaccess::UserSliceReader;
-use core::fmt;
-use core::fmt::Formatter;
 use core::marker::PhantomData;
 use core::ops::Deref;
 
@@ -76,9 +75,9 @@ impl<D, F> Deref for FormatAdapter<D, F> {
 
 impl<D, F> Writer for FormatAdapter<D, F>
 where
-    F: Fn(&D, &mut Formatter<'_>) -> fmt::Result + 'static,
+    F: Fn(&D, &mut fmt::Formatter<'_>) -> fmt::Result + 'static,
 {
-    fn write(&self, fmt: &mut Formatter<'_>) -> fmt::Result {
+    fn write(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         // SAFETY: FormatAdapter<_, F> can only be constructed if F is inhabited
         let f: &F = unsafe { materialize_zst() };
         f(&self.inner, fmt)