avformat/segafilm: Fix current_sample after seeking and avio_seek return type

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/segafilm.c

@@ -296,13 +296,14 @@ static int film_read_seek(AVFormatContext *s, int stream_index, int64_t timestam
 {
     FilmDemuxContext *film = s->priv_data;
     AVStream *st = s->streams[stream_index];
+    int64_t pos;
     int ret = av_index_search_timestamp(st, timestamp, flags);
     if (ret < 0)
         return ret;
 
-    ret = avio_seek(s->pb, st->index_entries[ret].pos, SEEK_SET);
-    if (ret < 0)
-        return ret;
+    pos = avio_seek(s->pb, st->index_entries[ret].pos, SEEK_SET);
+    if (pos < 0)
+        return pos;
 
     film->current_sample = ret;