Remove unnecessary cast in cabi_dealloc (#991)

Author: andrzejressel

crates/rust/src/lib.rs

@@ -386,7 +386,7 @@ pub unsafe fn cabi_dealloc(ptr: *mut u8, size: usize, align: usize) {
         return;
     }
     let layout = alloc::Layout::from_size_align_unchecked(size, align);
-    alloc::dealloc(ptr as *mut u8, layout);
+    alloc::dealloc(ptr, layout);
 }
                     ",
                 );