Hermit: Fix unused_imports

Author: mkroening

library/std/src/sys/hermit/mutex.rs

@@ -2,7 +2,6 @@ use crate::cell::UnsafeCell;
 use crate::collections::VecDeque;
 use crate::hint;
 use crate::ops::{Deref, DerefMut, Drop};
-use crate::ptr;
 use crate::sync::atomic::{AtomicUsize, Ordering};
 use crate::sys::hermit::abi;
 

library/std/src/sys/hermit/rwlock.rs

@@ -1,6 +1,5 @@
 use crate::cell::UnsafeCell;
 use crate::sys::locks::{MovableCondvar, Mutex};
-use crate::sys_common::lazy_box::{LazyBox, LazyInit};
 
 pub struct RwLock {
     lock: Mutex,