cgo: fix incorrect print found by govet

R=golang-dev
CC=golang-dev
https://golang.org/cl/5445052

misc/cgo/test/helpers.go

@@ -29,7 +29,7 @@ var testPairs = []testPair{
 func testHelpers(t *testing.T) {
 	for _, pair := range testPairs {
 		if !reflect.DeepEqual(pair.Got, pair.Want) {
-			t.Errorf("%s: got %#v, want %#v", pair.Got, pair.Want)
+			t.Errorf("%s: got %#v, want %#v", pair.Name, pair.Got, pair.Want)
 		}
 	}
 }