vcl: fix ldp writev 0 vecs
vcl: fix ldp writev 0 vecs

Type: fix

Signed-off-by: Florin Coras <c9715e5cdf0718c2e9b10678757dfb027875eba2@cisco.com>
Change-Id: Iec5db8dcf3a019b731e15fd79d0208d6eb10943b

chrisy/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp