kernel_tainted test from ubuntu_boot failed on F/G

Failure started appearing in 5.8.0-43.49.

1. 02/10 14:14:25 INFO |ubuntu_boo:0042| Checking kernel tainted flags in /proc/sys/kernel/tainted
2. 02/10 14:14:25 INFO |ubuntu_boo:0046| ERROR: kernel tainted flag != 0: 2048
3. 02/10 14:14:25 INFO |ubuntu_boo:0046|
4. 02/10 14:14:25 ERROR| test:0414| Exception escaping from test:
5. Traceback (most recent call last):
6. File "/home/ubuntu/autotest/client/shared/test.py", line 411, in _exec
7. _call_test_function(self.execute, *p_args, **p_dargs)
8. File "/home/ubuntu/autotest/client/shared/test.py", line 823, in _call_test_function
9. return func(*args, **dargs)
10. File "/home/ubuntu/autotest/client/shared/test.py", line 291, in execute
11. postprocess_profiled_run, args, dargs)
12. File "/home/ubuntu/autotest/client/shared/test.py", line 212, in _call_run_once
13. self.run_once(*args, **dargs)
14. File "/home/ubuntu/autotest/client/tests/ubuntu_boot/ubuntu_boot.py", line 59, in run_once
15. raise error.TestFail()
16. TestFail