bindings: rust: clippy: drop unneeded conversions

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>

bindings/rust/gpiosim-sys/src/sim.rs

@@ -186,7 +186,7 @@ impl SimBank {
 
     fn set_num_lines(&self, num: usize) -> Result<()> {
         // SAFETY: `gpiosim_bank` is guaranteed to be valid here.
-        let ret = unsafe { gpiosim_bank_set_num_lines(self.bank, num.try_into().unwrap()) };
+        let ret = unsafe { gpiosim_bank_set_num_lines(self.bank, num) };
         if ret == -1 {
             Err(Error::OperationFailed(
                 OperationType::SimBankSetNumLines,

bindings/rust/libgpiod/src/event_buffer.rs

@@ -108,7 +108,7 @@ impl Buffer {
             gpiod::gpiod_line_request_read_edge_events(
                 request.request,
                 self.buffer,
-                self.events.len().try_into().unwrap(),
+                self.events.len(),
             )
         };