Use const instead of var

lib/browser/api/auto-updater/auto-updater-win.js

@@ -10,7 +10,7 @@ class AutoUpdater extends EventEmitter {
       return this.emitError('No update available, can\'t quit and install')
     }
     squirrelUpdate.processStart()
-    return app.quit()
+    app.quit()
   }
 
   getFeedURL () {
@@ -39,15 +39,12 @@ class AutoUpdater extends EventEmitter {
       this.updateAvailable = true
       this.emit('update-available')
       squirrelUpdate.update(this.updateURL, (error) => {
-        var date, releaseNotes, version
         if (error != null) {
           return this.emitError(error)
         }
-        releaseNotes = update.releaseNotes
-        version = update.version
-
-        // Following information is not available on Windows, so fake them.
-        date = new Date()
+        const {releaseNotes, version} = update
+        // Date is not available on Windows, so fake it.
+        const date = new Date()
         this.emit('update-downloaded', {}, releaseNotes, version, date, this.updateURL, () => {
           this.quitAndInstall()
         })
@@ -58,7 +55,7 @@ class AutoUpdater extends EventEmitter {
   // Private: Emit both error object and message, this is to keep compatibility
   // with Old APIs.
   emitError (message) {
-    return this.emit('error', new Error(message), message)
+    this.emit('error', new Error(message), message)
   }
 }