Bug#16056813-MEMORY LEAK ON FILTERED SLAVE

Back porting fix from mysql-5.5

sql/rpl_utility.cc:
  Resetting last_added to NULL to avoid memory leak

sql/rpl_utility.cc

 /*
-   Copyright (c) 2006, 2012, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2006, 2013, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -280,6 +280,7 @@ void Deferred_log_events::rewind()
       Log_event *ev= *(Log_event **) dynamic_array_ptr(&array, i);
       delete ev;
     }
+    last_added= NULL;
     if (array.elements > array.max_element)
       freeze_size(&array);
     reset_dynamic(&array);