Fix cast between differently-aligned pointers

[peterjoel]

Fixes the following error, reported by clippy:

error: casting from `*const u8` to a more-strictly-aligned pointer (`*const usize`) (1 < 8 bytes)
  --> src/kbindings.rs:59:16
   |
59 |         &mut *((u as *const usize).offset(1) as *mut T)
   |                ^^^^^^^^^^^^^^^^^^^
   |

[rsdy]

Thanks a lot for this batch of PRs, really good stuff!

[peterjoel]

@rsdy No worries! Are you actively using this crate in production?

[rsdy]

We are, but not every part of the library. It's been lacking some love recently as it is generally quite stable on the code paths that we do use.