Get NIC name by "ip -o link"

"ip -o addr" doesn't include MAC address for Ubuntu 14 and CentOS 7.
"ip -o link" is a good substitute, since we're not looking for IP addresses
in this procedure.
Initial procedure is called "get_nic_name_by_ip", and the new is
"get_nic_name_by_mac"

Change-Id: Id070a51a3b496b8b746e27f7833f61282b25736e
3 files changed