ices/89682-2.rs: fixed with no errors

[github-actions]

Issue: rust-lang/rust#89682

#![feature(allocator_api)]
use core::alloc::{AllocError, Allocator, Layout};
use core::ptr::NonNull;

struct ZST;
unsafe impl Allocator for &ZST {
    fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
        todo!()
    }
    unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
        todo!()
    }
}
fn main() {
    let _ = Box::<i32, &ZST>::new_in(43, &ZST);
}

=== stdout ===
=== stderr ===
warning: unused variable: `layout`
 --> /home/runner/work/glacier/glacier/ices/89682-2.rs:7:24
  |
7 |     fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
  |                        ^^^^^^ help: if this is intentional, prefix it with an underscore: `_layout`
  |
  = note: `#[warn(unused_variables)]` on by default

warning: unused variable: `ptr`
  --> /home/runner/work/glacier/glacier/ices/89682-2.rs:10:33
   |
10 |     unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
   |                                 ^^^ help: if this is intentional, prefix it with an underscore: `_ptr`

warning: unused variable: `layout`
  --> /home/runner/work/glacier/glacier/ices/89682-2.rs:10:51
   |
10 |     unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
   |                                                   ^^^^^^ help: if this is intentional, prefix it with an underscore: `_layout`

warning: 3 warnings emitted

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