winebuild: Don't segfault when running without arguments

[Dmitry Timoshkov]

André Hentschel <nerv at dawncrow.de> wrote:

> -    if (!spec->dll_name)  /* set default name from file name */
> +    if (!spec->dll_name && spec->dll_name)  /* set default name from file name */
>      {
>          char *p;
>          spec->dll_name = xstrdup( spec->file_name );

Did you intend to check for spec->file_name?

-- 
Dmitry.