Optimize get_instance() calls/assignments
diff --git a/system/core/Model.php b/system/core/Model.php
index 1eb6f90..11e6075 100644
--- a/system/core/Model.php
+++ b/system/core/Model.php
@@ -59,8 +59,7 @@
 	 */
 	public function __get($key)
 	{
-		$CI =& get_instance();
-		return $CI->$key;
+		return get_instance()->$key;
 	}
 
 }