This patch will fix usage counting of logical channel. Also it adds
usage counter debugging.
The use counter is increased on loaction update request. The counter is
not decreased when location update responds (mm_rx_id_resp()), but if
subscriber is authorized, it will be decreased on
release_loc_update_req(). If lchan closes, the location update is also
released (release_loc_update_req()), also if the location update times
out.
In case of a channel connection failure with cause 0x18, the logical
channel is not released if usage counter of lchan is not 0.