Minor changes to readhis.rs to prevent warnings

Author: Osspial

examples/readhid.rs

@@ -29,15 +29,12 @@ use hidapi::HidApi;
 fn main() {
 
     let api = HidApi::new().unwrap();
-
-    let devices = api.devices();
 
     let mut joystick = api.open(1103, 45320).unwrap();
 
     loop {
         let data = joystick.read().unwrap();
 
-
         let mut data_string = String::new();
 
         for u in data {