library/StatsD_Checker: make logging messages more readable

Change-Id: I0484f36184fe3724c57cedcf203894d701b91605
diff --git a/library/StatsD_Checker.ttcn b/library/StatsD_Checker.ttcn
index 1c8fd12..8ace150 100644
--- a/library/StatsD_Checker.ttcn
+++ b/library/StatsD_Checker.ttcn
@@ -153,14 +153,14 @@
 			continue;
 		}
 		if (not f_compare_expect(metric, exp.expect)) {
-			log("EXP mismatch: ", metric, exp.expect);
+			log("EXP mismatch: ", metric, " vs ", exp.expect);
 			result := {
 				kind := e_Mismatched,
 				idx := i
 			};
 			break;
 		} else {
-			log("EXP match: ", metric, exp.expect);
+			log("EXP match: ", metric, " vs ", exp.expect);
 			result := {
 				kind := e_Matched,
 				idx := i