nm_channel_fsm: Fix innocuous transition not permitted log error

Event NM_EV_OML_DOWN in allstate will transition to Disabled
NotInstalled state. In the case where that is the current state, there's
really no change but we didn't allow the transition. Let's allow it
since it doesn't hurt and get rid of error messages when a BTS
disconnects.

Fixes: OS#4831
Change-Id: Ia5b7c88ff89e68ec5086d24f6ee20a8b3b2d994d
1 file changed