BTS_Tests: cosmetic: use setverdict() in f_sacch_{present,missing}()

This eliminates the need for using log2str() and improves readability.

Change-Id: Iaf9b03fb81ec4fa2ca4f0a0b2f0b50491c6a9d80
Related: SYS#5838, OS#4008, OS#4009
diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index b311da1..5741458 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -1090,7 +1090,8 @@
 		}
 	[] L1CTL.receive { repeat; }
 	[] T_sacch.timeout {
-		Misc_Helpers.f_shutdown(__BFILE__, __LINE__, fail, log2str("Timeout waiting for SACCH ", l3_exp));
+		setverdict(fail, "Timeout waiting for SACCH ", l3_exp);
+		Misc_Helpers.f_shutdown(__BFILE__, __LINE__);
 		}
 	}
 }
@@ -1105,7 +1106,8 @@
 	[] L1CTL.receive(tr_L1CTL_DATA_IND(g_chan_nr, tr_RslLinkID_SACCH(0))) -> value dl {
 		var octetstring l3 := substr(dl.payload.data_ind.payload, 4, 19);
 		if (match(l3, l3_exp)) {
-			Misc_Helpers.f_shutdown(__BFILE__, __LINE__, fail, log2str("Received unexpected SACCH ", dl));
+			setverdict(fail, "Received unexpected SACCH ", dl);
+			Misc_Helpers.f_shutdown(__BFILE__, __LINE__);
 		} else {
 			repeat;
 		}