update IPC fifo sample code

Guo Wenxue

2018-12-05 bd11641d0c07695581ce372a61c7c1cd767ee132

 ch5_multiplexing/socket_server_poll.c

@@ -100,12 +100,12 @@
        rv = poll(fds_array, max+1, -1);

        if(rv < 0)

        {

            printf("select failure: %s\n", strerror(errno));

            printf("poll failure: %s\n", strerror(errno));

            break;

        }

        else if(rv == 0)

        {

            printf("select get timeout\n");

            printf("poll get timeout\n");

            continue;

        }