fix error message when file "disappears"

go/qst.go

@@ -91,7 +91,7 @@ func runCmd(file string, runner *Runner) {
	for {
		info, err := os.Stat(file)
		if os.IsNotExist(err) {
			log.Fatalf("`%s' disappeared, exiting")
			log.Fatalf("`%s' disappeared, exiting", file)
		}
		mtime := info.ModTime()