Fix warnings

src/maybe_future.rs

@@ -106,7 +106,7 @@ pub mod blocking {
         }
 
         #[cfg(not(any(feature = "smol", feature = "tokio")))]
-        fn spawn(f: impl FnOnce() -> R + Send + 'static) -> Self {
+        fn spawn(_f: impl FnOnce() -> R + Send + 'static) -> Self {
             panic!("Awaiting blocking syscall without an async runtime: enable the `smol` or `tokio` feature of nusb.");
         }
     }

src/platform/linux_usbfs/device.rs

@@ -551,7 +551,7 @@ fn request_configuration(fd: &OwnedFd) -> Result<u8, ()> {
         Ok(1) => {
             let active_config = dst[0];
             debug!("Obtained active configuration for fd {} from GET_CONFIGURATION request: {active_config}", fd.as_raw_fd());
-            return Ok(active_config);
+            Ok(active_config)
         }
         Ok(n) => {
             warn!("GET_CONFIGURATION request returned unexpected length: {n}, expected 1");