finish standardizing!

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

@@ -30,10 +30,10 @@ var spawnUpdate = function (args, detached, callback) {
   stdout = ''
   stderr = ''
   spawnedProcess.stdout.on('data', function (data) {
-    return stdout += data
+    stdout += data
   })
   spawnedProcess.stderr.on('data', function (data) {
-    return stderr += data
+    stderr += data
   })
   errorEmitted = false
   spawnedProcess.on('error', function (error) {