statistics: remove one unused var

[winoros]

What problem does this PR solve?

Issue Number: close #xxx

Problem Summary:

What changed and how does it work?

This var only has set-variable operations.

Check List

Tests

• [x] Unit test
• [ ] Integration test
• [ ] Manual test (add detailed scripts or steps below)
• [ ] No need to test

  • [ ] I checked and no code files have been changed.

Side effects

• [ ] Performance regression: Consumes more CPU
• [ ] Performance regression: Consumes more Memory
• [ ] Breaking backward compatibility

Documentation

• [ ] Affects user behaviors
• [ ] Contains syntax changes
• [ ] Contains variable changes
• [ ] Contains experimental features
• [ ] Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 73.1065%. Comparing base (8d9e67b) to head (02070b2). :warning: Report is 3572 commits behind head on master.

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #52263        +/-   ##
================================================
+ Coverage   70.7570%   73.1065%   +2.3495%     
================================================
  Files          1491       1674       +183     
  Lines        440116     532918     +92802     
================================================
+ Hits         311413     389598     +78185     
- Misses       109272     120511     +11239     
- Partials      19431      22809      +3378     

Flag	Coverage Δ
integration	54.2336% <ø> (?)
unit	73.3427% <ø> (+1.5866%)	:arrow_up:

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

Components	Coverage Δ
dumpling	∅ <ø> (∅)
parser	∅ <ø> (∅)
br	67.5629% <ø> (+11.7106%)	:arrow_up:

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[hawkingrei]

/retest

[hawkingrei]

/hold

[hawkingrei]

/retest

[hawkingrei]

/unhold

[hawkingrei]

/retest

[hawkingrei]

/retest

[ti-chi-bot[bot]]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: hawkingrei, hi-rustin

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• ~~pkg/statistics/OWNERS~~ [hawkingrei,hi-rustin]

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[ti-chi-bot[bot]]

[LGTM Timeline notifier]

Timeline:

• 2024-04-01 00:27:09.406175934 +0000 UTC m=+230890.933716482: :ballot_box_with_check: agreed by hawkingrei.
• 2024-04-11 06:34:12.304061292 +0000 UTC m=+1116913.831601837: :ballot_box_with_check: agreed by hi-rustin.

[hawkingrei]

/retest

[ti-chi-bot[bot]]

@winoros: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
idc-jenkins-ci-tidb/check_dev_2	02070b26cb13a60475a9117b5c5fa79196e3f5a5	link	true	/test check-dev2
pull-integration-realcluster-test-next-gen	02070b26cb13a60475a9117b5c5fa79196e3f5a5	link	true	/test pull-integration-realcluster-test-next-gen
pull-unit-test-next-gen	02070b26cb13a60475a9117b5c5fa79196e3f5a5	link	true	/test pull-unit-test-next-gen

Full PR test history. Your PR dashboard.

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