[rsl] Set the release state from within the lchan class

Currently our GSM04.11 code is closing the link for SAPI=3
and this would mean that the whole channel would be scheduled
for close... where we only want to close everything when freeing
the lchan or handling an error.
diff --git a/openbsc/src/chan_alloc.c b/openbsc/src/chan_alloc.c
index cd48e43..118deca 100644
--- a/openbsc/src/chan_alloc.c
+++ b/openbsc/src/chan_alloc.c
@@ -348,6 +348,7 @@
 			lchan->conn.use_count);
 
 	DEBUGP(DRLL, "%s Recycling Channel\n", gsm_lchan_name(lchan));
+	rsl_lchan_set_state(lchan, LCHAN_S_REL_REQ);
 	rsl_release_request(lchan, 0);
 	return 1;
 }