ituh263dec: use macro instead of #if

libavcodec/ituh263dec.c

@@ -456,8 +456,7 @@ static int h263_decode_block(MpegEncContext * s, int16_t * block,
         }
     } else if (s->mb_intra) {
         /* DC coef */
-        if(s->codec_id == AV_CODEC_ID_RV10){
-#if CONFIG_RV10_DECODER
+        if (CONFIG_RV10_DECODER && s->codec_id == AV_CODEC_ID_RV10) {
           if (s->rv10_version == 3 && s->pict_type == AV_PICTURE_TYPE_I) {
             int component, diff;
             component = (n <= 3 ? 0 : n - 4 + 1);
@@ -477,7 +476,6 @@ static int h263_decode_block(MpegEncContext * s, int16_t * block,
                 if (level == 255)
                     level = 128;
           }
-#endif
         }else{
             level = get_bits(&s->gb, 8);
             if((level&0x7F) == 0){