bindings: rust: clippy: drop unnecessary casts

bindings: rust: clippy: drop unnecessary casts

Fixes clippy warnings on these lines.

Applied the suggested fix using:

    cargo clippy --fix

clippy version: clippy 0.1.70 (90c5418 2023-05-31).

Reported-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20230612154055.56556-1-warthog618@gmail.com
Signed-off-by: Erik Schilling <erik.schilling@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>