CRM-13156, fixed the wrong property

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* CRM-13156: CRM_Core_BAO_EntityTag::getEntitiesByTag enumerates for incorrect field
  http://issues.civicrm.org/jira/browse/CRM-13156

CRM/Core/BAO/EntityTag.php

@@ -268,18 +268,18 @@ class CRM_Core_BAO_EntityTag extends CRM_Core_DAO_EntityTag {
    *
    * @param object  $tag    an object of a tag.
    *
-   * @return  array   $contactIds    array of contact ids
+   * @return  array   $entityIds    array of entity ids
    * @access public
    */
   function getEntitiesByTag($tag) {
-    $contactIds = array();
+    $entityIds = array();
     $entityTagDAO = new CRM_Core_DAO_EntityTag();
     $entityTagDAO->tag_id = $tag->id;
     $entityTagDAO->find();
     while ($entityTagDAO->fetch()) {
-      $contactIds[] = $entityTagDAO->contact_id;
+      $entityIds[] = $entityTagDAO->entity_id;
     }
-    return $contactIds;
+    return $entityIds;
   }
 
   /**