there are some memory leak：

1、event_data memory leak in function run_ping_ip46_address

event_data memory is allocated in vlib_process_get_events,but it is not freed after event is received.

2、event_data memory leak in function ip_arp_add_del_command_fn

3、event_data memory leak in function ip4_probe_neighbor_wait

I will modify these memory leak together