Change memory ordering in System wrapper example

library/std/src/alloc.rs

@@ -93,7 +93,7 @@ pub use alloc_crate::alloc::*;
 ///
 /// ```rust
 /// use std::alloc::{System, GlobalAlloc, Layout};
-/// use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
+/// use std::sync::atomic::{AtomicUsize, Ordering::Relaxed};
 ///
 /// struct Counter;
 ///
@@ -103,22 +103,22 @@ pub use alloc_crate::alloc::*;
 ///     unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
 ///         let ret = System.alloc(layout);
 ///         if !ret.is_null() {
-///             ALLOCATED.fetch_add(layout.size(), SeqCst);
+///             ALLOCATED.fetch_add(layout.size(), Relaxed);
 ///         }
 ///         ret
 ///     }
 ///
 ///     unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
 ///         System.dealloc(ptr, layout);
-///         ALLOCATED.fetch_sub(layout.size(), SeqCst);
+///         ALLOCATED.fetch_sub(layout.size(), Relaxed);
 ///     }
 /// }
 ///
 /// #[global_allocator]
 /// static A: Counter = Counter;
 ///
 /// fn main() {
-///     println!("allocated bytes before main: {}", ALLOCATED.load(SeqCst));
+///     println!("allocated bytes before main: {}", ALLOCATED.load(Relaxed));
 /// }
 /// ```
 ///