sgsn: fix a typo in comment

Change-Id: I061aba5af1e466b33472c9f829b982823bcff71e
diff --git a/sgsn/SGSN_Tests.ttcn b/sgsn/SGSN_Tests.ttcn
index 0b439ec..e1d35c5 100644
--- a/sgsn/SGSN_Tests.ttcn
+++ b/sgsn/SGSN_Tests.ttcn
@@ -460,7 +460,7 @@
 
 	BSSGP.send(attach_req);
 	f_gmm_auth(umts_aka_challenge, force_gsm_sres);
-	/* Expect MSC to perform LU with HLR */
+	/* Expect SGSN to perform LU with HLR */
 	f_gmm_gsup_lu_isd();
 
 	BSSGP.receive(tr_BD_L3_MT(tr_GMM_ATTACH_ACCEPT('001'B, ?, ?))) -> value bd {