fix: use std::hint::black_box

This function has been stablized, and thus the criterion version of it
has been marked as deprecated.

Signed-off-by: Patrick Roy <roypat@amazon.co.uk>

Author: roypat

benches/fdt.rs

@@ -8,11 +8,13 @@ extern crate criterion;
 extern crate linux_loader;
 extern crate vm_memory;
 
+use std::hint::black_box;
+
 use linux_loader::configurator::fdt::FdtBootConfigurator;
 use linux_loader::configurator::{BootConfigurator, BootParams};
 use vm_memory::{ByteValued, GuestAddress, GuestMemoryMmap};
 
-use criterion::{black_box, Criterion};
+use criterion::Criterion;
 
 const MEM_SIZE: usize = 0x100_0000;
 const FDT_MAX_SIZE: usize = 0x20;

benches/x86_64/mod.rs

@@ -11,6 +11,7 @@ extern crate linux_loader;
 extern crate vm_memory;
 
 use std::fs::File;
+use std::hint::black_box;
 use std::io::{Cursor, Read};
 
 use linux_loader::configurator::pvh::PvhBootConfigurator;
@@ -22,7 +23,7 @@ use linux_loader::loader::elf::Elf;
 use linux_loader::loader::KernelLoader;
 use vm_memory::{Address, GuestAddress, GuestMemoryMmap};
 
-use criterion::{black_box, Criterion};
+use criterion::Criterion;
 
 const MEM_SIZE: usize = 0x100_0000;
 const E820_RAM: u32 = 1;