sync: track upstream loom changes (#1407)

tokio-sync/src/loom.rs

@@ -1,4 +1,4 @@
-pub(crate) mod futures {
+pub(crate) mod future {
     pub(crate) use crate::task::AtomicWaker;
 }
 

tokio-sync/src/mpsc/chan.rs

@@ -1,6 +1,6 @@
 use super::list;
 use crate::loom::{
-    futures::AtomicWaker,
+    future::AtomicWaker,
     sync::atomic::AtomicUsize,
     sync::{Arc, CausalCell},
 };

tokio-sync/src/semaphore.rs

@@ -9,7 +9,7 @@
 //! `Pending`. The task is woken once a permit becomes available.
 
 use crate::loom::{
-    futures::AtomicWaker,
+    future::AtomicWaker,
     sync::{
         atomic::{AtomicPtr, AtomicUsize},
         CausalCell,