fix: remove sample logos and apply suggestions from code review

Author: hirale

app/code/core/Mage/Oauth2/controllers/Adminhtml/Oauth2/ClientController.php

@@ -71,7 +71,7 @@ public function preDispatch()
 
     /**
      * Index action - display list of OAuth2 clients
-     * 
+     *
      * @return void
      */
     public function indexAction()
@@ -83,7 +83,7 @@ public function indexAction()
 
     /**
      * New client action - display form for creating new OAuth2 client
-     * 
+     *
      * @return void
      */
     public function newAction()
@@ -107,7 +107,7 @@ public function newAction()
 
     /**
      * Edit client action - display form for editing existing OAuth2 client
-     * 
+     *
      * @return void
      */
     public function editAction()
@@ -128,8 +128,8 @@ public function editAction()
 
     /**
      * Save client action - save new or update existing OAuth2 client
-     * 
-     * @return void
+     *
+     * @return mixed
      */
     public function saveAction()
     {
@@ -169,7 +169,7 @@ public function saveAction()
 
     /**
      * Delete client action
-     * 
+     *
      * @return void
      */
     public function deleteAction()

app/code/core/Mage/Oauth2/controllers/AuthorizeController.php

@@ -22,7 +22,7 @@ class Mage_Oauth2_AuthorizeController extends Mage_Oauth2_Controller_BaseControl
     /**
      * Index action
      *
-     * @return void
+     * @return mixed
      */
     public function indexAction()
     {

app/code/core/Mage/Oauth2/controllers/DeviceController.php

@@ -22,7 +22,7 @@ class Mage_Oauth2_DeviceController extends Mage_Oauth2_Controller_BaseController
     /**
      * Request action - Generate device and user codes
      *
-     * @return void
+     * @return mixed
      */
     public function requestAction()
     {
@@ -44,7 +44,7 @@ public function requestAction()
     /**
      * Authorize action - Process device authorization
      *
-     * @return void
+     * @return  mixed
      */
     public function authorizeAction()
     {
@@ -101,7 +101,7 @@ public function authorizeAction()
     /**
      * Poll action - Check authorization status and provide access token
      *
-     * @return void
+     * @return mixed
      */
     public function pollAction()
     {