staging/lustre/mdc: fix procfs fops

mdc_kuc_fops is missing open/release handlers. I fixed it before but
somehow forgot to amend to the patch sent out. Sorry...

Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>