dvdnav: don't probe stdin (this just removes a silly error message)

modules/access/dvdnav.c

@@ -1459,6 +1459,9 @@ static int ProbeDVD( demux_t *p_demux, char *psz_name )
         return VLC_SUCCESS;
     }
 
+    if( !strcmp( psz_name, "-" ) ) /* stdin -> file access */
+        return VLC_EGENERIC;
+
     if( (i_fd = utf8_open( psz_name, O_RDONLY |O_NONBLOCK, 0666 )) == -1 )
     {
         return VLC_SUCCESS; /* Let dvdnav_open() do the probing */