netinet/tcp.h: add new tcp_info fields from linux v5.4

tcpi_rcv_ooopack for tracking connection quality:

  linux commit f9af2dbbfe01def62765a58af7fbc488351893c3
  tcp: Add TCP_INFO counter for packets received out-of-order

tcpi_snd_wnd peer window size for diagnosing tcp performance problems:

  linux commit 8f7baad7f03543451af27f5380fc816b008aa1f2
  tcp: Add snd_wnd to TCP_INFO

include/netinet/tcp.h

@@ -234,6 +234,8 @@ struct tcp_info {
 	uint64_t tcpi_bytes_retrans;
 	uint32_t tcpi_dsack_dups;
 	uint32_t tcpi_reord_seen;
+	uint32_t tcpi_rcv_ooopack;
+	uint32_t tcpi_snd_wnd;
 };
 
 #define TCP_MD5SIG_MAXKEYLEN    80