misc: fix dispatching actions twice when mapDispatchToProps is used

react/features/toolbox/components/Toolbar.web.js

          * @returns {Object} Dispatched action.
          */
         _onMouseOut() {
-            return dispatch(setToolbarHovered(false));
+            dispatch(setToolbarHovered(false));
         },
 
         /**
          * @returns {Object} Dispatched action.
          */
         _onMouseOver() {
-            return dispatch(setToolbarHovered(true));
+            dispatch(setToolbarHovered(true));
         }
     };
 }