Fixed incorrect comment in YANG file.
Fixed incorrect comment in YANG file.

Change-Id: I4754261aa02f4c54544e9719068bd884a06cf378
Signed-off-by: Shigeru Yasuda <4286dc62f6b184926d282535950a80f031d65860@da.jp.nec.com>

opendaylight/vtn,opendaylight/vtn,opendaylight/vtn,opendaylight/vtn,opendaylight/vtn,opendaylight/vtn,opendaylight/vtn