[fix] memory leak when the value of posix semaphore is zero.

components/libc/posix/ipc/semaphore.c

@@ -39,7 +39,9 @@ static void posix_sem_delete(sem_t *psem)
         posix_sem_list = psem->next;
 
         rt_sem_delete(psem->sem);
-        rt_free(psem);
+
+        if(psem->unamed == 0)
+            rt_free(psem);
 
         return;
     }
@@ -55,7 +57,9 @@ static void posix_sem_delete(sem_t *psem)
 
             /* delete RT-Thread mqueue */
             rt_sem_delete(psem->sem);
-            rt_free(psem);
+
+            if(psem->unamed == 0)
+                rt_free(psem);
 
             return ;
         }
@@ -107,8 +111,6 @@ RTM_EXPORT(sem_close);
 
 int sem_destroy(sem_t *sem)
 {
-    rt_err_t result;
-
     if ((!sem) || !(sem->unamed))
     {
         rt_set_errno(EINVAL);
@@ -118,8 +120,7 @@ int sem_destroy(sem_t *sem)
 
     /* lock posix semaphore list */
     rt_sem_take(&posix_sem_lock, RT_WAITING_FOREVER);
-    result = rt_sem_trytake(sem->sem);
-    if (result != RT_EOK)
+    if(rt_list_len(&sem->sem->parent.suspend_thread) != 0)
     {
         rt_sem_release(&posix_sem_lock);
         rt_set_errno(EBUSY);