Do not return values above AVPROBE_SCORE_MAX from probe().

Originally committed as revision 19857 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/ncdec.c

@@ -35,7 +35,7 @@ static int nc_probe(AVProbeData *probe_packet)
     size = AV_RL16(probe_packet->buf + 5);
 
     if (size + 20 > probe_packet->buf_size)
-        return 3*AVPROBE_SCORE_MAX/2;
+        return AVPROBE_SCORE_MAX/4;
 
     if (AV_RB32(probe_packet->buf+16+size) == NC_VIDEO_FLAG)
         return AVPROBE_SCORE_MAX;