fftools/ffmpeg_enc: simplify opaque_ref check

Found-while-revieweing: CID1520670 Dereference after null check

Sponsored-by: Sovereign Tech Fund
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 97b2ab15de)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

fftools/ffmpeg_enc.c

@@ -492,7 +492,7 @@ void enc_stats_write(OutputStream *ost, EncStats *es,
 
     const FrameData *fd;
 
-    if ((frame && frame->opaque_ref) || (pkt && pkt->opaque_ref)) {
+    if (frame ? frame->opaque_ref : pkt->opaque_ref) {
         fd   = (const FrameData*)(frame ? frame->opaque_ref->data : pkt->opaque_ref->data);
         tbi  = fd->dec.tb;
         ptsi = fd->dec.pts;