Fix vent_data memory leak in function run_ping_ip46_address (VPP-966)
Fix vent_data memory leak in function run_ping_ip46_address (VPP-966)

Change-Id: I05d0c8310aa86480a3d283f45e115284c4b4ebd5
Signed-off-by: dongjuan <1b774497373669e00e0aec18f4d97e19aaab3049@zte.com.cn>

FDio/vpp,vpp-dev/vpp,vpp-dev/vpp,vpp-dev/vpp,chrisy/vpp,FDio/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,chrisy/vpp,chrisy/vpp,vpp-dev/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,vpp-dev/vpp,vpp-dev/vpp,FDio/vpp,FDio/vpp,FDio/vpp,vpp-dev/vpp,FDio/vpp