2014/testing/test1/string_test.go: fix swapped arguments

Fixes golang/go#9213.

Change-Id: I58c7da89780baeb1cc7d3811e3d89a4dae406777
Reviewed-on: https://go-review.googlesource.com/2230
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/2014/testing/test1/string_test.go b/2014/testing/test1/string_test.go
index c458ffe..6061882 100644
--- a/2014/testing/test1/string_test.go
+++ b/2014/testing/test1/string_test.go
@@ -9,6 +9,6 @@
 	const s, sep, want = "chicken", "ken", 4
 	got := strings.Index(s, sep)
 	if got != want {
-		t.Errorf("Index(%q,%q) = %v; want %v", s, sep, want, got)
+		t.Errorf("Index(%q,%q) = %v; want %v", s, sep, got, want)
 	}
 }