Verify addrs only against ports with fixed IPs

To verify a port's mac and IP address, the list of neutron ports is
used. We cannot check against ports without fixed IP addresses, so
exclude them.

Change-Id: Ib81ab42cdbae3132af735b0020ca59d22b71ebaf
Closes-bug: #1300322
Merge "Verify addrs only against ports with fixed IPs"