rust/hpet: Fix a clippy error

Carge clippy complained about:

error: casts from `u8` to `u32` can be expressed infallibly using `From`

So use `From` to convert `u8` to `u32`.

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250414144943.1112885-10-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 file changed