RSL: get rid of some compiler warnings
RSL: get rid of some compiler warnings

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