BUG#21132 (Slave fails to reconnect on update_slave_list)

This is a one liner which will fix semantics if SHOW SLAVE HOSTS to 
display the list of slaves currently registered on the host on which
it was issued.


sql/slave.cc:
  Remove call to update_slave_list() which was executing "SHOW SLAVE
  HOSTS" on master and populating slave_list based on the output.

sql/slave.cc

@@ -2020,7 +2020,7 @@ pthread_handler_t handle_slave_io(void *arg)
       on with life.
     */
     thd->proc_info = "Registering slave on master";
-    if (register_slave_on_master(mysql) ||  update_slave_list(mysql, mi))
+    if (register_slave_on_master(mysql))
       goto err;
   }