update hal.h to fix turn_led not definition bug

Guo Wenxue

2019-06-27 4fe5c3b3f767773b8bfcc7f4bdba977a12239f7e

 apue/2.Socket/socket_client.c

@@ -109,7 +109,8 @@
          }
       }

       //printf("Read %d bytes data from server: '%s'\n", rv, buf);

       sleep(5);
    }