Update rtthread.h

Correct comments about doxygen format

include/rtthread.h

@@ -46,7 +46,7 @@ extern "C" {
  * @addtogroup KernelObject
  */
 
-/*@{*/
+/**@{*/
 
 /*
  * kernel object interface
@@ -72,13 +72,13 @@ void rt_object_take_sethook(void (*hook)(struct rt_object *object));
 void rt_object_put_sethook(void (*hook)(struct rt_object *object));
 #endif
 
-/*@}*/
+/**@}*/
 
 /**
  * @addtogroup Clock
  */
 
-/*@{*/
+/**@{*/
 
 /*
  * clock & timer interface
@@ -116,13 +116,13 @@ void rt_timer_check(void);
 void rt_timer_timeout_sethook(void (*hook)(struct rt_timer *timer));
 #endif
 
-/*@}*/
+/**@}*/
 
 /**
  * @addtogroup Thread
  */
 
-/*@{*/
+/**@{*/
 
 /*
  * thread interface
@@ -187,13 +187,13 @@ rt_uint16_t rt_critical_level(void);
 void rt_scheduler_sethook(void (*hook)(rt_thread_t from, rt_thread_t to));
 #endif
 
-/*@}*/
+/**@}*/
 
 /**
  * @addtogroup MM
  */
 
-/*@{*/
+/**@{*/
 
 /*
  * memory management interface
@@ -266,13 +266,13 @@ void *rt_memheap_realloc(struct rt_memheap* heap, void* ptr, rt_size_t newsize);
 void rt_memheap_free(void *ptr);
 #endif
 
-/*@}*/
+/**@}*/
 
 /**
  * @addtogroup IPC
  */
 
-/*@{*/
+/**@{*/
 
 #ifdef RT_USING_SEMAPHORE
 /*
@@ -371,14 +371,14 @@ rt_err_t rt_mq_recv(rt_mq_t    mq,
 rt_err_t rt_mq_control(rt_mq_t mq, rt_uint8_t cmd, void *arg);
 #endif
 
-/*@}*/
+/**@}*/
 
 #ifdef RT_USING_DEVICE
 /**
  * @addtogroup Device
  */
 
-/*@{*/
+/**@{*/
 
 /*
  * device (I/O) system interface
@@ -411,7 +411,7 @@ rt_size_t rt_device_write(rt_device_t dev,
                           rt_size_t   size);
 rt_err_t  rt_device_control(rt_device_t dev, rt_uint8_t cmd, void *arg);
 
-/*@}*/
+/**@}*/
 #endif
 
 #ifdef RT_USING_MODULE
@@ -419,7 +419,7 @@ rt_err_t  rt_device_control(rt_device_t dev, rt_uint8_t cmd, void *arg);
  * @addtogroup Module
  */
 
-/*@{*/
+/**@{*/
 
 /*
  * module interface
@@ -449,7 +449,7 @@ rt_err_t rt_module_destroy(rt_module_t module);
  */
 int rt_system_module_init(void);
 
-/*@}*/
+/**@}*/
 #endif
 
 /*
@@ -481,7 +481,7 @@ void rt_components_board_init(void);
  * @addtogroup KernelService
  */
 
-/*@{*/
+/**@{*/
 
 /*
  * general kernel service
@@ -534,7 +534,7 @@ void rt_assert_set_hook(void (*hook)(const char* ex, const char* func, rt_size_t
 void rt_assert_handler(const char* ex, const char* func, rt_size_t line);
 #endif /* RT_DEBUG */
 
-/*@}*/
+/**@}*/
 
 #ifdef __cplusplus
 }