Fix a crash on oom when decoding hevc.

libavcodec/hevc.c

@@ -2597,6 +2597,7 @@ static av_cold int hevc_decode_free(AVCodecContext *avctx)
 
     pic_arrays_free(s);
 
+    if (lc)
         av_freep(&lc->edge_emu_buffer);
     av_freep(&s->md5_ctx);