From the Pod::Checker manual:
> RETURN VALUE
> podchecker returns the number of POD syntax errors found or
> -1 if there were no POD commands at all found in the file.
Reviewed-by: David von Oheimb <david.von.oheimb@siemens.com>
(Merged from https://github.com/openssl/openssl/pull/13416)
