Fixing a few clippy issues.

Author: Narsil

src/lib.rs

@@ -356,7 +356,6 @@ pub use crate::windows::grab as _grab;
 ///     }
 /// }
 /// ```
-#[cfg(feature = "unstable_grab")]
 pub fn grab<T>(callback: T) -> Result<(), GrabError>
 where
     T: Fn(Event) -> Option<Event> + 'static,

src/windows/grab.rs

@@ -22,7 +22,8 @@ unsafe extern "system" fn raw_callback(code: i32, param: usize, lpdata: isize) -
                 time: SystemTime::now(),
                 name,
             };
-            if let Some(callback) = &mut GLOBAL_CALLBACK {
+            let ptr = &raw mut GLOBAL_CALLBACK;
+            if let Some(callback) = &mut *ptr {
                 if callback(event).is_none() {
                     // https://stackoverflow.com/questions/42756284/blocking-windows-mouse-click-using-setwindowshookex
                     // https://android.developreference.com/article/14560004/Blocking+windows+mouse+click+using+SetWindowsHookEx()

src/windows/listen.rs

@@ -33,7 +33,8 @@ unsafe extern "system" fn raw_callback(code: c_int, param: WPARAM, lpdata: LPARA
                 time: SystemTime::now(),
                 name,
             };
-            if let Some(callback) = &mut GLOBAL_CALLBACK {
+            let ptr = &raw mut GLOBAL_CALLBACK;
+            if let Some(callback) = &mut *ptr {
                 callback(event);
             }
         }