lavf/avidec: Do not test for bitrate <= INT_MAX.

AVCodecContext->bit_rate is int64_t since 7404f3bd

Unbreaks non-interleaved detection of v210 4k avi files, broken since 0eec40b7.
Reported-by: Xavier Càmara, Centre de Conservació i Restauració, Filmoteca de Catalunya

libavformat/avidec.c

@@ -456,7 +456,7 @@ static int calculate_bitrate(AVFormatContext *s)
             continue;
         duration = st->index_entries[j-1].timestamp - st->index_entries[0].timestamp;
         bitrate = av_rescale(8*len, st->time_base.den, duration * st->time_base.num);
-        if (bitrate <= INT_MAX && bitrate > 0) {
+        if (bitrate > 0) {
             st->codecpar->bit_rate = bitrate;
         }
     }