fix the regression due to e45f382e51c9a3d57a6d8c01cec9e70f7ca364fd

OFcontroller is not started due to:

e45f382e51c9a3d57a6d8c01cec9e70f7ca364fd
Author: Isaku Yamahata <yamahata@valinux.co.jp>
Date:   Fri Nov 22 16:45:59 2013 +0900

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>