remove warnings

Originally committed as revision 2245 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/4xm.c

@@ -551,7 +551,7 @@ static int decode_i_frame(FourXContext *f, uint8_t *buf, int length){
     uint16_t *dst= (uint16_t*)f->current_picture.data[0];
     const int stride= f->current_picture.linesize[0]>>1;
     const int bitstream_size= get32(buf);
-    const int token_count= get32(buf + bitstream_size + 8);
+    const int token_count __attribute((unused)) = get32(buf + bitstream_size + 8);
     int prestream_size= 4*get32(buf + bitstream_size + 4);
     uint8_t *prestream= buf + bitstream_size + 12;