rust: export PointerWrapper from kernel

Previously, only the concrete type could be specified for the data
parameter of kernel::file::Operations method implementations. Exporting
PointerWrapper now allows specifying the data parameter in terms of the
associated type, Self::Data.

Signed-off-by: John Baublitz <[email protected]>

Author: jbaublitz

rust/kernel/lib.rs

@@ -106,7 +106,7 @@ pub use build_error::build_error;
 pub use crate::error::{to_result, Error, Result};
 pub use crate::types::{
     bit, bits_iter, ARef, AlwaysRefCounted, Bool, Either, Either::Left, Either::Right, False, Mode,
-    Opaque, ScopeGuard, True,
+    Opaque, PointerWrapper, ScopeGuard, True,
 };
 
 use core::marker::PhantomData;