lib: fix some unnecessary_cast clippy lint

warning: casting raw pointers to the same type and constness is unnecessary (`*mut V` -> `*mut V`)
   --> library\alloc\src\collections\btree\map\entry.rs:357:31
    |
357 |                 let val_ptr = root.borrow_mut().push(self.key, value) as *mut V;
    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `root.borrow_mut().push
(self.key, value)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast

warning: casting to the same type is unnecessary (`usize` -> `usize`)
   --> library\alloc\src\ffi\c_str.rs:411:56
    |
411 |             let slice = slice::from_raw_parts_mut(ptr, len as usize);
    |                                                        ^^^^^^^^^^^^ help: try: `len`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast

warning: casting raw pointers to the same type and constness is unnecessary (`*mut T` -> `*mut T`)
   --> library\alloc\src\slice.rs:516:25
    |
516 |                         (buf.as_mut_ptr() as *mut T).add(buf.len()),
    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `buf.as_mut_ptr()`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast

warning: casting raw pointers to the same type and constness is unnecessary (`*mut T` -> `*mut T`)
   --> library\alloc\src\slice.rs:537:21
    |
537 |                     (buf.as_mut_ptr() as *mut T).add(buf.len()),
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `buf.as_mut_ptr()`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast

warning: casting raw pointers to the same type and constness is unnecessary (`*const ()` -> `*const ()`)
   --> library\alloc\src\task.rs:151:13
    |
151 |             waker as *const (),
    |             ^^^^^^^^^^^^^^^^^^ help: try: `waker`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast

warning: casting raw pointers to the same type and constness is unnecessary (`*const ()` -> `*const ()`)
   --> library\alloc\src\task.rs:323:13
    |
323 |             waker as *const (),
    |             ^^^^^^^^^^^^^^^^^^ help: try: `waker`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast

warning: casting to the same type is unnecessary (`usize` -> `usize`)
   --> library\std\src\sys_common\net.rs:110:21
    |
110 |             assert!(len as usize >= mem::size_of::<c::sockaddr_in>());
    |                     ^^^^^^^^^^^^ help: try: `len`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast

warning: casting to the same type is unnecessary (`usize` -> `usize`)
   --> library\std\src\sys_common\net.rs:116:21
    |
116 |             assert!(len as usize >= mem::size_of::<c::sockaddr_in6>());
    |                     ^^^^^^^^^^^^ help: try: `len`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast

1 files changed, 2 insertions, 2 deletions

diff --git a/library/alloc/src/task.rs b/library/alloc/src/task.rs
index b40768a52b6..a3fa6585a37 100644
--- a/library/alloc/src/task.rs
+++ b/library/alloc/src/task.rs
@@ -148,7 +148,7 @@ fn raw_waker<W: Wake + Send + Sync + 'static>(waker: Arc<W>) -> RawWaker {
     unsafe fn clone_waker<W: Wake + Send + Sync + 'static>(waker: *const ()) -> RawWaker {
         unsafe { Arc::increment_strong_count(waker as *const W) };
         RawWaker::new(
-            waker as *const (),
+            waker,
             &RawWakerVTable::new(clone_waker::<W>, wake::<W>, wake_by_ref::<W>, drop_waker::<W>),
         )
     }
@@ -320,7 +320,7 @@ fn local_raw_waker<W: LocalWake + 'static>(waker: Rc<W>) -> RawWaker {
     unsafe fn clone_waker<W: LocalWake + 'static>(waker: *const ()) -> RawWaker {
         unsafe { Rc::increment_strong_count(waker as *const W) };
         RawWaker::new(
-            waker as *const (),
+            waker,
             &RawWakerVTable::new(clone_waker::<W>, wake::<W>, wake_by_ref::<W>, drop_waker::<W>),
         )
     }