Why we delete this part code? Does ARP cache contains invalid information?

verify_ip_address_ownership is called in every get_address().  get_addresss() also called in many function. Which means we will have more arping command in network.  If we have more VM running arping command at same time,  it may break our network.

So we'd better keep thses code.  If ARP cache contains invalid information, we can try to fix why it contains invalid information.  

One suggest from IT is that  we can delete the out of time log in ARP cache after guest shutdown.

Please correct me if I make anything wrong.

Thanks for your patch.