Follow-up to 6f55c00e72ca6db130a84fe92218f73a777428f4

- Fixed a memory leak (bugreport:7885), thanks to rosfus
  http://hercules.ws/board/tracker/issue-7885-memory-leaks-found-at-20131205-20h31m31s-rev-13617/

Signed-off-by: Haru <haru@dotalux.com>