BTS_Tests: use as_l1_exp_lapdm() in f_TC_rll_est_req()

Change-Id: Ic0ecef07385621e0f0fbdae67daad95ef628cdd5
Related: SYS#4895, OS#4941
diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index 8874d85..9289673 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -6324,21 +6324,7 @@
 	RSL.send(ts_RSL_EST_REQ(g_chan_nr, tc.link_id));
 	T.start;
 	alt {
-	[] L1CTL.receive(tr_L1CTL_DATA_IND(g_chan_nr, ?)) -> value dl {
-		var LapdmFrame lapdm;
-		var octetstring l2 := dl.payload.data_ind.payload;
-		if (dl.dl_info.link_id.c == SACCH) {
-			/* remove L1 header */
-			l2 := substr(l2, 2, lengthof(l2)-2);
-		}
-		lapdm.ab := dec_LapdmFrameAB(l2);
-		if (match(lapdm, tr_LAPDm_SABM(tc.sapi, cr_MT_CMD, true, ''O))) {
-			setverdict(pass);
-		} else {
-			repeat;
-		}
-		}
-	[] L1CTL.receive { repeat; }
+	[] as_l1_exp_lapdm(tr_LAPDm_SABM(tc.sapi, cr_MT_CMD, true, ''O));
 	[] T.timeout {
 		Misc_Helpers.f_shutdown(__BFILE__, __LINE__, fail, "Timeout waiting for SABM");
 		}