rust: error: use core::alloc::LayoutError

Use `core::alloc::LayoutError` instead of `alloc::alloc::LayoutError` in
preparation to get rid of Rust's alloc crate.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

Author: Danilo Krummrich

rust/kernel/error.rs

@@ -6,7 +6,7 @@
 
 use crate::{alloc::AllocError, str::CStr};
 
-use alloc::alloc::LayoutError;
+use core::alloc::LayoutError;
 
 use core::fmt;
 use core::num::NonZeroI32;