lavf/dump: Remove superfluous cast.

libavformat/dump.c

@@ -595,7 +595,7 @@ void av_dump_format(AVFormatContext *ic, int index,
         }
         av_log(NULL, AV_LOG_INFO, ", bitrate: ");
         if (ic->bit_rate)
-            av_log(NULL, AV_LOG_INFO, "%"PRId64" kb/s", (int64_t)ic->bit_rate / 1000);
+            av_log(NULL, AV_LOG_INFO, "%"PRId64" kb/s", ic->bit_rate / 1000);
         else
             av_log(NULL, AV_LOG_INFO, "N/A");
         av_log(NULL, AV_LOG_INFO, "\n");