Change log level from info to debug

Modify the log level to debug as the message in this case
is more suited for debug level.

Change-Id: I9cf6498d405fea7dd7fc14cef894527285889d30

networking_arista/ml2/mechanism_arista.py

@@ -411,7 +411,7 @@ class AristaDriver(driver_api.MechanismDriver):
                 device_owner.startswith('baremetal')]):
             return True
 
-        LOG.info(_LI('Unsupported device owner: %s'), device_owner)
+        LOG.debug('Unsupported device owner: %s', device_owner)
 
     def _network_owner_tenant(self, context, network_id, tenant_id):
         tid = tenant_id