glg.go
func (g *Glg) Fatalf(format string, val ...interface{}) {
	err := g.out(FATAL, format, val...)
	if err != nil {
		err = g.Error(err.Error())
		if err != nil {
			panic(err)
		}
	}
	exit(1)
}
func (g *Glg) Fatalf(format string, val ...interface{}) {
	err := g.out(FATAL, format, val...)
	if err != nil {
		err = g.Error(err.Error())
		if err != nil {
			panic(err)
		}
	}
	exit(1)
}
// Fatalf outputs formatted Failed log and exit program