1. No need to rollback the interface creation in teh distributed router
driver. It is rolled back on the plugin level. the Double rollback causes
a new error to be raised.
2. In the plugin level - do not alert on the rollback faliure.
It may be legit
2. In the plugin level raise a proper error to neutron, instead of the
internal one.
Change-Id: I129f595d6cd17cd0af62fc9e2855451b97e73ff0
511404073c