avcodec/utvideodec: enable unchecked bitreader

inner reader loop becomes 16% faster
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/utvideodec.c

@@ -27,6 +27,8 @@
 #include <inttypes.h>
 #include <stdlib.h>
 
+#define UNCHECKED_BITSTREAM_READER 1
+
 #include "libavutil/intreadwrite.h"
 #include "avcodec.h"
 #include "bswapdsp.h"