Remove functions not present in older libbpf versions

packet-exchange/src/recv_packet.c

@@ -252,7 +252,6 @@ void init_xdp_recv(char *network_if) {
       .comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS,
       .frame_size = FRAME_SIZE,
       .frame_headroom = XSK_UMEM__DEFAULT_FRAME_HEADROOM,
-      .flags = 0,
   };
   struct bpf_object *obj;
   struct bpf_map *map;
@@ -337,8 +336,7 @@ int recv_xdp_packet(struct timespec * ts) {
     if (ret != received)
       err("xsk_ring_prod__reserve() failed");
 
-    *xsk_ring_prod__fill_addr(&xdp_socket.umem.fq, idx) =
-        xsk_umem__extract_addr(addr);
+    *xsk_ring_prod__fill_addr(&xdp_socket.umem.fq, idx) = addr;
 
     xsk_ring_prod__submit(&xdp_socket.umem.fq, received);
   }