fsm: log tweak: upon free, say 'Freeing instance'

Logging 'Release' is a bit ambiguous. At first I tought a subscriber
connection was being released, IMHO 'Freeing instance' better describes that
we are freeing an osmo_fsm_inst.

Change-Id: I5cf99707d2ba5620b2988f777fa39cc806ec0212
1 file changed