Test_mutex_multi_thread_timeout failed occasionally on RISCV

[xuchang-vivo]

As follow:

[       OK ] test_mutex_multi_thread_priority1
[ RUN      ] test_mutex_multi_thread_timeout
panicked at ../../kernel/kernel/src/sync/mutex.rs:593:17:
assertion failed: !result
Oops: assertion failed: !result

[xuchang-vivo]

kernel/kernel/src/sync/mutex.rs

Lines 592 to 610 in a06ea55

	let result = mutex.pend_for(Tick(5));
	assert!(!result);
	pend_flag.fetch_add(1, Ordering::SeqCst);
	wake(&pend_flag);
	}
	};
	let consumer = thread::spawn(closure);
	let succ = mutex.pend_for(Tick(10));
	assert!(succ);
	assert_eq!(mutex.nesting_count(), 1);
	pend_flag.fetch_add(1, Ordering::SeqCst);
	wake(&pend_flag);
	let start = Tick::now();
	let mut current = start;
	while current.0 - start.0 < 10 {
	scheduler::relinquish_me();
	current = Tick::now();
	}
	mutex.post();

There is a possibility that the logic on line 592 is executed only after the logic on line 610 has finished executing.