strings: revert accidental example change from CL 153840

Change-Id: I2ff29aa9909be3062fcd5f65af261f5d8c46fbc1
Reviewed-on: https://go-review.googlesource.com/c/153843Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/strings/example_test.go

@@ -199,7 +199,7 @@ func ExampleRepeat() {
 
 func ExampleReplace() {
 	fmt.Println(strings.Replace("oink oink oink", "k", "ky", 2))
-	fmt.Println(strings.ReplaceAll("oink oink oink", "oink", "moo"))
+	fmt.Println(strings.Replace("oink oink oink", "oink", "moo", -1))
 	// Output:
 	// oinky oinky oink
 	// moo moo moo