fix clippy lints

src/lib.rs

@@ -111,9 +111,9 @@ fn sine() {
 		for testfreq in (0..30).map(|x| (x * 100) as f32) {
 			let p = Parameters::new(testfreq, 8000, 8000);
 			let testmag = p.mag(&buf[..]);
-			println!("{:4}: {:12.3}", testfreq, testmag);
+			println!("{testfreq:4}: {testmag:12.3}");
 			if (freq - testfreq).abs() > 100. {
-				println!("{} > 10*{}", mag, testmag);
+				println!("{mag} > 10*{testmag}");
 				assert!(mag > 10. * testmag);
 			}
 		}