[class-properties] Remove unnecessary return and temp variable (#8123)

* Remove unnecessary temp variable

* Update tests

packages/babel-plugin-transform-react-constant-elements/test/fixtures/constant-elements/class-assign-unreferenced-param-deopt/output.mjs

@@ -6,17 +6,19 @@ var _ref =
 
 class BugReport extends React.Component {
   constructor(...args) {
-    var _temp;
+    super(...args);
 
-    return _temp = super(...args), this.thisWontWork = ({
+    this.thisWontWork = ({
       color
     }) => data => {
       return <div color={color}>does not reference data</div>;
-    }, this.thisWorks = ({
+    };
+
+    this.thisWorks = ({
       color
     }) => data => {
       return <div color={color}>{data}</div>;
-    }, _temp;
+    };
   }
 
   render() {

packages/babel-plugin-transform-react-constant-elements/test/fixtures/constant-elements/member-expression-this/output.js

@@ -4,13 +4,15 @@ var _ref =
 
 class Component extends React.Component {
   constructor(...args) {
-    var _temp;
+    super(...args);
+
+    this.subComponent = () => _ref;
 
     var _ref2 =
     /*#__PURE__*/
     <this.subComponent />;
 
-    return _temp = super(...args), this.subComponent = () => _ref, this.render = () => _ref2, _temp;
+    this.render = () => _ref2;
   }
 
 }

packages/babel-plugin-transform-react-constant-elements/test/fixtures/constant-elements/member-expression/output.js

@@ -12,9 +12,9 @@ var _ref2 =
 
 class Component extends React.Component {
   constructor(...args) {
-    var _temp;
+    super(...args);
 
-    return _temp = super(...args), this.render = () => _ref2, _temp;
+    this.render = () => _ref2;
   }
 
 }