testing/fs:remove the usleep of evend_fd read to solve the questiong of sem wait

Remove unnecessary usleep(1000) in the read thread of eventfd test.
The eventfd read operation will block and wait for data naturally via semaphore, no additional delay is needed.

Signed-off-by: wangxingxing <wangxingxing@xiaomi.com>

testing/testsuites/kernel/fs/cases/fs_eventfd_test.c

@@ -54,7 +54,6 @@ __attribute__((unused)) static void *threadfunc(void *args)
   for (int i = 0; i < 5; i++)
     {
       read(fd, &eventfd01_buffer, sizeof(eventfd_t));
-      usleep(1000);
     }
 
   return 0;