Fix two warnings (one of them a clippy warning)

Author: steffahn

rand_chacha/src/chacha.rs

@@ -388,7 +388,7 @@ mod test {
     #[test]
     fn test_chacha_serde_format_stability() {
         let j = r#"{"seed":[4,8,15,16,23,42,4,8,15,16,23,42,4,8,15,16,23,42,4,8,15,16,23,42,4,8,15,16,23,42,4,8],"stream":27182818284,"word_pos":314159265359}"#;
-        let r: ChaChaRng = serde_json::from_str(&j).unwrap();
+        let r: ChaChaRng = serde_json::from_str(j).unwrap();
         let j1 = serde_json::to_string(&r).unwrap();
         assert_eq!(j, j1);
     }

src/distributions/uniform.rs

@@ -1430,7 +1430,7 @@ mod tests {
     #[test]
     #[should_panic]
     fn test_float_overflow() {
-        Uniform::from(::core::f64::MIN..::core::f64::MAX);
+        let _ = Uniform::from(::core::f64::MIN..::core::f64::MAX);
     }
 
     #[test]