Bugfix for shared event source (#12129)

For some reason our eslint configuration is not working correctly
and a bug has become apparent when trying to backport this to 1.12.

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

web_src/js/features/eventsource.sharedworker.js

           // How this has happened I don't understand...
           // deregister from that source
           const count = source.deregister(port);
-            // Clean-up
+          // Clean-up
           if (count === 0) {
             source.close();
             sourcesByUrl[source.url] = null;
         source.register(port);
         sourcesByUrl[url] = source;
         sourcesByPort[port] = source;
-        return;
       } else if (event.data.type === 'listen') {
         const source = sourcesByPort[port];
         source.listen(event.data.eventType);
-        return;
       } else if (event.data.type === 'close') {
         const source = sourcesByPort[port];
 
           sourcesByUrl[source.url] = null;
           sourcesByPort[port] = null;
         }
-        return;
       } else if (event.data.type === 'status') {
         const source = sourcesByPort[port];
         if (!source) {
           return;
         }
         source.status(port);
-        return;
       } else {
         // just send it back
         port.postMessage({
           type: 'error',
           message: `received but don't know how to handle: ${event.data}`,
         });
-        return;
       }
     });
     port.start();

web_src/js/features/notification.js

         type: 'start',
         url: `${window.location.origin}${AppSubUrl}/user/events`,
       });
-      worker.port.addEventListener('message', (e) => {
-        if (!e.data || !e.data.type) {
-          console.error(e);
+      worker.port.addEventListener('message', (event) => {
+        if (!event.data || !event.data.type) {
+          console.error(event);
           return;
         }
         if (event.data.type === 'notification-count') {
-          receiveUpdateCount(e.data);
-          return;
+          receiveUpdateCount(event.data);
         } else if (event.data.type === 'error') {
-          console.error(e.data);
-          return;
+          console.error(event.data);
         } else if (event.data.type === 'logout') {
-          if (e.data !== 'here') {
+          if (event.data !== 'here') {
             return;
           }
           worker.port.postMessage({
           });
           worker.port.close();
           window.location.href = AppSubUrl;
-          return;
-        } else {
-          return;
         }
       });
       worker.port.addEventListener('error', (e) => {