PR binutils/5713

    PR binutils/5713
        * strings.c (integer_arg): Delete function.
        (string_min): Initialise to 4.
        (main): Use strtoul to parse integer arguments.
        Move check for an invalid string length to after all the arguments
        have been parsed.
        (usage): Use indentation to indicate that -<n> is a another form
        of the --bytes= command line option.