RSL/LAPDM: make sure we do lapdm_channel_reset()
RSL/LAPDM: make sure we do lapdm_channel_reset()

this will free / flush any of the queued messages and give us a
clean start for the next user of the same lapdm channel.

geosphere/osmo-bts,tacooper/osmo-bts,shimaore/osmo-bts,telenoobie/osmo-bts,tacooper/osmo-bts,telenoobie/osmo-bts,osmocom/osmo-bts,telenoobie/osmo-bts,osmocom/osmo-bts,geosphere/osmo-bts,geosphere/osmo-bts,shimaore/osmo-bts,geosphere/osmo-bts,osmocom/osmo-bts,telenoobie/osmo-bts,shimaore/osmo-bts,shimaore/osmo-bts