avformat/pdvenc: Don't silently truncate value

This muxer seems to intend to support output that does
not begin at zero (instead of e.g. just hardcoding
nb_frames_pos to 16). But then it is possible
that avio_seek() returns values > INT_MAX even
though the part of the file written by us can not
exceed this value. So the return value of avio_seek()
needs to be checked as 64bit integer and not silently
truncated to int.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavformat/pdvenc.c

@@ -158,7 +158,7 @@ static int pdv_write_trailer(AVFormatContext *s)
     PDVMuxContext *pdv = s->priv_data;
     int64_t payload_size = avio_tell(s->pb);
     const uint32_t table_gap = 4U * (pdv->max_frames - pdv->nb_frames);
-    int ret;
+    int64_t ret;
 
     if (payload_size < 0)
         return AVERROR(EIO);