fix minor unreachable code caused by t.Fatalf

[Abirdcfly]

https://pkg.go.dev/testing#T.Fatalf

Fatalf is equivalent to Logf followed by FailNow.

https://pkg.go.dev/testing#T.FailNow

FailNow marks the function as having failed and stops its execution by calling runtime.Goexit (which then runs all deferred calls in the current goroutine).

see https://go.dev/play/p/LkLbybLy_oi for example

package main

import (
	"testing"
)

func TestLastIndex(t *testing.T) {
	t.Fatalf("this line will print and exit")
	t.Fatalf("this line cant print")
}

/* output:
=== RUN   TestLastIndex
    prog.go:8: this line will print and exit
--- FAIL: TestLastIndex (0.00s)
FAIL

Program exited.
*/

[tonyghita]

Thanks!