There's no rollback support in AirWave. This is due to changes in the flat files maintained for graphing - improvements to these files do not allow rollback at all, other causes are updated RPM packages and database schema changes.
There's a short kb article that's attached to all upgrade announcements for this matter:
kb.airwave.com/?sid=50140000000Mf6w
Your best bet is to reinstall and restore a pre-upgrade backup.