More verbose error output for a failure in vcl.TestFQVersion().

pkg/varnish/vcl/vcl_test.go

@@ -241,7 +241,9 @@ func TestFQVersion(t *testing.T) {
 	if created, err := time.Parse(RFC3339Micro, versionSlice[3]); err != nil {
 		t.Fatal("FQVersion(): cannot parse timestamp", err)
 	} else if testSpec.Created != created {
-		t.Fatal("FQVersion(): timestamp != Spec.Created", fqVersion)
+		t.Fatalf("FQVersion(): timestamp != Spec.Created (%s) "+
+			"got %s want %s", versionSlice[3], testSpec.Created,
+			created)
 	}
 
 	noversionSpec := Spec{