remove a division from STOP_TIMER

Originally committed as revision 6315 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavutil/common.h

@@ -386,7 +386,7 @@ tend= read_time();\
       tcount++;\
   }else\
       tskip_count++;\
-  if(256*256*256*64%(tcount+tskip_count)==0){\
+  if(((tcount+tskip_count)&(tcount+tskip_count-1))==0){\
       av_log(NULL, AV_LOG_DEBUG, "%"PRIu64" dezicycles in %s, %d runs, %d skips\n", tsum*10/tcount, id, tcount, tskip_count);\
   }\
 }