avformat/idcin: Remove redundant chunk size check

Fixes CID1138438
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/idcin.c

@@ -307,8 +307,6 @@ static int idcin_read_packet(AVFormatContext *s,
         }
         /* skip the number of decoded bytes (always equal to width * height) */
         avio_skip(pb, 4);
-        if (chunk_size < 4)
-            return AVERROR_INVALIDDATA;
         chunk_size -= 4;
         ret= av_get_packet(pb, pkt, chunk_size);
         if (ret < 0)