createnet: use vmmInterface.get_name() instead of vmmInterface.name

It fixes this exception:

Traceback (most recent call last):
  File "virt-manager/virtManager/host.py", line 467, in add_network
    self.addnet.show(self.topwin)
  File "virt-manager/virtManager/createnet.py", line 102, in show
    self.reset_state()
  File "virt-manager/virtManager/createnet.py", line 180, in reset_state
    devnames.append(iface.name)
AttributeError: 'vmmInterface' object has no attribute 'name'

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

virtManager/createnet.py

@@ -174,8 +174,8 @@ class vmmCreateNetwork(vmmGObjectUI):
         for nodedev in self.conn.get_nodedevs("net"):
             devnames.append(nodedev.name)
         for iface in self.conn.list_interfaces():
-            if iface.name not in devnames:
-                devnames.append(iface.name)
+            if iface.get_name() not in devnames:
+                devnames.append(iface.get_name())
 
         for name in devnames:
             fw_model.append([_("Physical device %s") % name, name])