DAOS-19647 chk: race between chk_iv_ns_destroy and CHK IV handler

[Nasf-Fan]

chk_iv_ns_destroy() may trigger ds_iv_ns_cleanup() without synchronize with others, as to release some IV entries while Cart can still invoke chk_iv_ent_refresh() on them.

The patch uses the existing barrier ds_iv_ns_stop() to handle the race.

Features: recovery

Steps for the author:

• Commit message follows the guidelines.
• Appropriate Features or Test-tag pragmas were used.
• Appropriate Functional Test Stages were run.
• At least two positive code reviews including at least one code owner from each category referenced in the PR.
• Testing is complete. If necessary, forced-landing label added and a reason added in a comment.

After all prior steps are complete:

• Gatekeeper requested (daos-gatekeeper added as a reviewer).

[github-actions]

Ticket title is 'CHK IV segmentation fault on UCX during CHK leader resume test'
Status is 'In Progress'
https://daosio.atlassian.net/browse/DAOS-19647

[daosbuild3]

Test stage Functional Hardware Medium MD on SSD completed with status FAILURE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net//job/daos-stack/job/daos/view/change-requests/job/PR-19156/1/execution/node/1959/log

[daosbuild3]

Test stage Functional Hardware Medium MD on SSD completed with status FAILURE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net//job/daos-stack/job/daos/view/change-requests/job/PR-19156/2/execution/node/1770/log

[daosbuild3]

Test stage Functional Hardware Medium Verbs Provider MD on SSD completed with status FAILURE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net//job/daos-stack/job/daos/view/change-requests/job/PR-19156/2/execution/node/1857/log

[Nasf-Fan]

Test stage Functional Hardware Medium MD on SSD completed with status FAILURE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net//job/daos-stack/job/daos/view/change-requests/job/PR-19156/2/execution/node/1770/log

DMGCheckStartCornerCaseTest.test_two_pools_corrupted failed for DAOS-18773.

[Nasf-Fan]

Test stage Functional Hardware Medium Verbs Provider MD on SSD completed with status FAILURE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net//job/daos-stack/job/daos/view/change-requests/job/PR-19156/2/execution/node/1857/log

DaosCoreTest.test_daos_rebuild_ec failed for DAOS-19396.