[pthreads] Fix the sem_trywait issue.

components/libc/pthreads/semaphore.c

@@ -362,7 +362,7 @@ int sem_trywait(sem_t *sem)
         return -1;
     }
 
-    result = rt_sem_take(sem->sem, RT_WAITING_FOREVER);
+    result = rt_sem_take(sem->sem, 0);
     if (result == -RT_ETIMEOUT)
     {
         rt_set_errno(EAGAIN);