DAOS-15863 container: fix a race for container cache (#15038)

[gnailzenh]

• DAOS-15863 container: fix a race for container cache

while destroying a container, cont_child_destroy_one() releases its own refcount before waiting, if another ULT releases its refcount, which is the last one, wakes up the waiting ULT and frees it ds_cont_child straightaway, because no one else has refcount.

When the waiting ULT is waken up, it will try to change the already freed ds_cont_child.

This patch changes the LRU eviction logic and fixes this race.

Before requesting gatekeeper:

• Two review approvals and any prior change requests have been resolved.
• Testing is complete and all tests passed or there is a reason documented in the PR why it should be force landed and forced-landing tag is set.
• Features: (or Test-tag*) commit pragma was used or there is a reason documented that there are no appropriate tags for this PR.
• Commit messages follows the guidelines outlined here.
• Any tests skipped by the ticket being addressed have been run and passed in the PR.

Gatekeeper:

• You are the appropriate gatekeeper to be landing the patch.
• The PR has 2 reviews by people familiar with the code, including appropriate owners.
• Githooks were used. If not, request that user install them and check copyright dates.
• Checkpatch issues are resolved. Pay particular attention to ones that will show up on future PRs.
• All builds have passed. Check non-required builds for any new compiler warnings.
• Sufficient testing is done. Check feature pragmas and test tags and that tests skipped for the ticket are run and now pass with the changes.
• If applicable, the PR has addressed any potential version compatibility issues.
• Check the target branch. If it is master branch, should the PR go to a feature branch? If it is a release branch, does it have merge approval in the JIRA ticket.
• Extra checks if forced landing is requested
  • Review comments are sufficiently resolved, particularly by prior reviewers that requested changes.
  • No new NLT or valgrind warnings. Check the classic view.
  • Quick-build or Quick-functional is not used.
• Fix the commit message upon landing. Check the standard here. Edit it to create a single commit. If necessary, ask submitter for a new summary.

[github-actions]

Ticket title is '1-./erasurecode/online_rebuild.py:EcodOnlineRebuild.test_ec_online_rebuild, 1-./ior/hard_rebuild.py:EcodIorHardRebuild.test_ec_ior_hard_online_rebuild tests fail due to container destroy error (-2001).'
Status is 'Resolved'
Labels: '2.6.0rc2,2.6.0rc3,ci_2.6_weekly,ci_master_weekly,md_on_ssd,triaged,weekly_test'
https://daosio.atlassian.net/browse/DAOS-15863