net/pkt: fix build error when NET_PKT_WRITE_BUFFERS disable

fix build error.

Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>

net/pkt/pkt.h

@@ -90,9 +90,8 @@ struct pkt_conn_s
   FAR struct devif_callback_s *sndcb;
 #  if CONFIG_NET_SEND_BUFSIZE > 0
   int32_t  sndbufs;               /* Maximum amount of bytes queued in send */
-  sem_t    sndsem;                /* Semaphore signals send completion */
 #  endif
-
+  sem_t    sndsem;                /* Semaphore signals send completion */
 #endif
 
   /* Read-ahead buffering.

net/pkt/pkt_conn.c

@@ -139,7 +139,7 @@ void pkt_free(FAR struct pkt_conn_s *conn)
 
   dq_rem(&conn->sconn.node, &g_active_pkt_connections);
 
-#ifdef CONFIG_NET_CAN_WRITE_BUFFERS
+#ifdef CONFIG_NET_PKT_WRITE_BUFFERS
   /* Free the write queue */
 
   iob_free_queue(&conn->write_q);

net/pkt/pkt_sendmsg_buffered.c

@@ -66,7 +66,6 @@
  *
  ****************************************************************************/
 
-#if CONFIG_NET_SEND_BUFSIZE > 0
 static void pkt_sendbuffer_notify(FAR struct pkt_conn_s *conn)
 {
   int val = 0;
@@ -77,7 +76,6 @@ static void pkt_sendbuffer_notify(FAR struct pkt_conn_s *conn)
       nxsem_post(&conn->sndsem);
     }
 }
-#endif
 
 /****************************************************************************
  * Name: psock_send_eventhandler
@@ -175,9 +173,7 @@ static uint16_t psock_send_eventhandler(FAR struct net_driver_s *dev,
 
       flags &= ~PKT_POLL;
 
-#if CONFIG_NET_SEND_BUFSIZE > 0
       pkt_sendbuffer_notify(conn);
-#endif
     }
 
   return flags;

net/pkt/pkt_sockif.c

@@ -125,8 +125,10 @@ static int pkt_sockif_alloc(FAR struct socket *psock)
 
   conn->type = psock->s_proto;
 
-#if defined(CONFIG_NET_PKT_WRITE_BUFFERS) && CONFIG_NET_SEND_BUFSIZE > 0
+#ifdef CONFIG_NET_PKT_WRITE_BUFFERS
+#  if CONFIG_NET_SEND_BUFSIZE > 0
   conn->sndbufs = CONFIG_NET_SEND_BUFSIZE;
+#  endif
   nxsem_init(&conn->sndsem, 0, 0);
 #endif