去除sal shut_down后释放socket导致close失败的问题

components/net/sal_socket/socket/net_sockets.c

@@ -106,8 +106,6 @@ int shutdown(int s, int how)
         error = -1;
     }
     
-    /* socket has been closed, delete it from file system fd */
-    fd_put(d);
     fd_put(d);
 
     return error;

components/net/sal_socket/src/sal_socket.c

@@ -701,8 +701,6 @@ int sal_shutdown(int socket, int how)
         error = -1;
     }
 
-    /* delete socket */
-    socket_delete(socket);
 
     return error;
 }