vfwcap: Replace deprecated av_destruct_packet() by av_free_packet()

libavdevice/vfwcap.c

@@ -230,7 +230,7 @@ static int vfw_read_close(AVFormatContext *s)
     pktl = ctx->pktl;
     while (pktl) {
         AVPacketList *next = pktl->next;
-        av_destruct_packet(&pktl->pkt);
+        av_free_packet(&pktl->pkt);
         av_free(pktl);
         pktl = next;
     }