Reviewing a va_list was not closed with va_end warning

[Coldfirex]

Howdy,
I noticed we are getting this on one of our files.

error: va_list 'args' was opening but not closed by va_end().  
return -1;

Here is the snippet of code:
output_data(const char *format, ...)

{
va_list args;
int len;
char *buf;

va_start(args, format);
if ((len = vasprintf(&buf, format, args)) == -1)
return -1;
output_datalen(buf, len);
va_end(args);
free(buf);
return (len);
}

I am new to this so pardon my ignorance. I got rid of the error by moving va_end before return -1; However, since its still called is this a non-issue, or just a best practice, etc.?

[Daniel Marjamäki]

I am not sure but it seems to be a false positive. I have created https://trac.cppcheck.net/ticket/10369