delete minor unreachable code caused by t.Fatal

[Abirdcfly]

Signed-off-by: Abirdcfly [email protected]

see https://go.dev/play/p/w4Xuilq-KvA for example:

package main

import (
	"testing"
)

func TestLastIndex(t *testing.T) {
	t.Fatalf("this line will print and exit")
	t.Errorf("this line can't print")
}

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

Program exited.
*/