mpegvideo_enc: use av_log() in debug code

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/mpegvideo_enc.c

@@ -4137,7 +4137,7 @@ if(block[j]){
 #ifdef REFINE_STATS
 count++;
 if(256*256*256*64 % count == 0){
-    printf("after_last:%d to_zero:%d from_zero:%d raise:%d lower:%d sign:%d xyp:%d/%d/%d\n", after_last, to_zero, from_zero, raise, lower, messed_sign, s->mb_x, s->mb_y, s->picture_number);
+    av_log(s->avctx, AV_LOG_DEBUG, "after_last:%d to_zero:%d from_zero:%d raise:%d lower:%d sign:%d xyp:%d/%d/%d\n", after_last, to_zero, from_zero, raise, lower, messed_sign, s->mb_x, s->mb_y, s->picture_number);
 }
 #endif
             run=0;