Fail on empty line of s-record.

[bicyclesonthemoon]

Some tools produce s-record (or hex) files which have an additonal empty line(s) at the end.
rl78flash will not accept such otherwise perfectly valid file.

It makes much more sense to accept these files than having to edit each file every time a software is released.
Empty lines can be safely ignored.

I am dealing with it by skiping the line if first character is '\r' or '\n':
in srec.c:
if ('S' != line[0])
{
if ('\r' == line[0] || '\n' == line[0])
{
break;
}
fprintf(stderr, "File format error (\"%s\")\n", line);
rc = SREC_FORMAT_ERROR;
break;
}
(I don't know why github is misformatting the indentation)

similarly for intel hex:
if (':' != line[0])
{
if ('\r' == line[0] || '\n' == line[0])
{
break;
}
fprintf(stderr, "File format error (\"%s\")\n", line);
rc = SREC_FORMAT_ERROR;
break;
}

(BTW, I wrote some questions in my pull request for intel hex support)

[bicyclesonthemoon]

Related to this issue:
When last line of srec file does not end with a newline character, the error message is misleading:
"Unable to parse file: line is too long\n".