style: linear(...) easing: Simplify piecewise linear implementation given parsing simplification

Differential Revision: https://phabricator.services.mozilla.com/D150163

components/style/values/computed/easing.rs

@@ -25,7 +25,6 @@ impl ComputedLinearStop {
         (
             x.output,
             x.input.into_rust().map(|x| x.0),
-            None,
         )
     }
 }