cluster: fix the unreleased RLock issue (#4355)

[ti-chi-bot]

This is an automated cherry-pick of #4355

Signed-off-by: Ryan Leung rleungx@gmail.com

What problem does this PR solve?

Closes #4354.

What is changed and how it works?

Release the RLock if it returns early.

Check List

Tests

• Unit test

Related changes

• Need to cherry-pick to the release branch

Release note

Fix the issue that the RLock is not released

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• disksing
• nolouch

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[nolouch]

/run-unit-tests

[codecov]

Codecov Report

Merging #4358 (9366849) into release-5.3 (c49fbde) will increase coverage by 0.00%.
The diff coverage is 0.00%.

@@             Coverage Diff              @@
##           release-5.3    #4358   +/-   ##
============================================
  Coverage        74.97%   74.98%           
============================================
  Files              264      264           
  Lines            27266    27267    +1     
============================================
+ Hits             20442    20445    +3     
- Misses            5013     5023   +10     
+ Partials          1811     1799   -12     

Flag	Coverage Δ
unittests	74.98% <0.00%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
server/cluster/cluster.go	83.25% <0.00%> (+0.13%)	⬆️
server/tso/local_allocator.go	64.86% <0.00%> (-13.52%)	⬇️
pkg/dashboard/adapter/manager.go	78.72% <0.00%> (-4.26%)	⬇️
pkg/etcdutil/etcdutil.go	84.70% <0.00%> (-3.53%)	⬇️
server/tso/allocator_manager.go	64.83% <0.00%> (-1.84%)	⬇️
server/schedule/operator_controller.go	83.50% <0.00%> (-1.23%)	⬇️
pkg/btree/btree.go	85.78% <0.00%> (-0.97%)	⬇️
server/core/storage.go	69.54% <0.00%> (ø)
client/client.go	72.02% <0.00%> (+0.23%)	⬆️
... and 6 more

---

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[nolouch]

/merge

[ti-chi-bot]

@nolouch: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: a433f8d

[nolouch]

/run-unit-tests