dyn TS, assignment: allow switch from PDCH with associated conn

Typically, an lchan that is released should no longer be associated with
subscriber connection. If that is the case, an S_LCHAN_UNEXPECTED_RELEASE is
triggered, which aborts, e.g., an ongoing assignment.

However, with dynamic timeslots, we may set lchan->conn and then start to
switch over from PDCH to a TCH mode, in which case it is perfectly fine to
release an lchan that is associated to a conn.

In lchan_free(), do not fire S_LCHAN_UNEXPECTED_RELEASE for a dyn TS that is
currently in switchover.

This is the second and last part to fix dynamic timeslots handling of the
gscon.

Related: OS#3211
Change-Id: Id7d9dd06451722eb328db77bb586826c954bd85c
1 file changed