Fix calling event listeners

src/grid-area.tsx

@@ -136,7 +136,7 @@ class GridArea extends PureComponent<GridAreaProps, {}> {
             [primaryLengthAttr]: maxPos - minPos,
           };
           
-          const tmpRect = (
+          return (
             <rect
               {...rectProps}
               key={i}
@@ -147,10 +147,6 @@ class GridArea extends PureComponent<GridAreaProps, {}> {
               onMouseOut={(ev) => { this.props.onValueMouseOut(ev, tmpValue) }}
             />
           );
-
-          return (
-            
-          );
         })}
       </g>
     );