Lib crash if trying to decode end-of-file marker

[Cyrille Meichel]

if trying this:

``package main

import (
"fmt"
"github.com/mash/go-intelhex"
)

func main() {
_, records := intelhex.ParseString(":00000001FF")
for record := range records {
fmt.Printf("%v\n", record)
}
}``

the program will crash

[Masakazu Ohtsuka]

Thanks for the feedback