[202405] Fix test_pfcwd_function on Mellanox platform

[bingwang-ms]

Description of PR

Summary:
This PR is to fix test issue caused by PR #15946

The code below is to ensure there is PFCWD triggered on new queues before checking syslog.

sonic-mgmt/tests/pfcwd/test_pfcwd_function.py

Lines 739 to 741 in 15bf903

	pytest_assert(wait_until(PFC_STORM_TIMEOUT, 2, 0,
	lambda: check_pfc_storm_state(dut, port, self.storm_hndle.pfc_queue_idx) != pfcwd_stats_before_test), # noqa: E501, E128
	"PFC storm state did not change as expected") # noqa: E127

The test is flaky after change in #15946 because the wait time is not enough for PFCWD to be triggered on new queues.

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• Test case(new/improvement)

Back port request

• 202012
• 202205
• 202305
• 202311
• 202405

Approach

What is the motivation for this PR?

This PR is to fix test issue caused by PR #15946

How did you do it?

Change the logic back while maintain compatibility with chassis.

How did you verify/test it?

The change is verified on a Mellanox platform.

collected 5 items                                                                                                                                                                                     

pfcwd/test_pfcwd_function.py::TestPfcwdFunc::test_pfcwd_actions[str2-msn4600c-acs-04]  ^H ^H ^H ^HPASSED                                                                                                    [ 20%]
pfcwd/test_pfcwd_function.py::TestPfcwdFunc::test_pfcwd_multi_port[str2-msn4600c-acs-04]  ^H ^H ^HPASSED                                                                                                 [ 40%]
pfcwd/test_pfcwd_function.py::TestPfcwdFunc::test_pfcwd_mmu_change[str2-msn4600c-acs-04]  ^H ^HPASSED                                                                                                 [ 60%]
pfcwd/test_pfcwd_function.py::TestPfcwdFunc::test_pfcwd_port_toggle[str2-msn4600c-acs-04]  ^H ^H ^HPASSED                                                                                                [ 80%]
pfcwd/test_pfcwd_function.py::TestPfcwdFunc::test_pfcwd_no_traffic[str2-msn4600c-acs-04] SKIPPED (This test is applicable only for cisco-8000 / Pfcwd tests skipped on m0/mx testbed.)          [100%]

Any platform specific information?

Mellanox platform specific.

Supported testbed topology if it's a new test case?

Not a new test.

Documentation

[mssonicbld]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[auspham]

LGTM, thanks for taking care of this