cosmetic: act lchan type: use constant instead of 0x00

Change-Id: Idc8afc4e52e189f474077899eef896381ce238f7
diff --git a/openbsc/src/libbsc/abis_rsl.c b/openbsc/src/libbsc/abis_rsl.c
index 8547e67..42adec9 100644
--- a/openbsc/src/libbsc/abis_rsl.c
+++ b/openbsc/src/libbsc/abis_rsl.c
@@ -1560,7 +1560,7 @@
 		gsm_lchant_name(lchan->type), gsm_chreq_name(chreq_reason),
 		rqd_ref->ra, rqd_ta);
 
-	rsl_chan_activate_lchan(lchan, 0x00, 0);
+	rsl_chan_activate_lchan(lchan, RSL_ACT_INTRA_IMM_ASS, 0);
 
 	return 0;
 }