BugFix #958 in OVSDB setting LLDP length to 0xffff

Manually cherry-picking https://git.opendaylight.org/gerrit/#/c/7144/4 to stable/hydrogen

Change-Id: I8f5193d7ac793b337422c53cbfaa237a26ee69c3
Signed-off-by: Madhu Venugopal <mavenugo@gmail.com>