statistics: fix ToHotPeersStat result when HotPeers is empty

[lhy1024]

Signed-off-by: lhy1024 admin@liudos.us

What problem does this PR solve?

Issue Number: Close #5598

What is changed and how does it work?

Check List

Tests

• Unit test

Release note

None.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• HunDunDM
• nolouch

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

The full list of commands accepted by this bot can be found here.

Reviewer can indicate their review by submitting an approval review.
Reviewer can cancel approval by submitting a request changes review.

[codecov]

Codecov Report

Base: 75.67% // Head: 75.52% // Decreases project coverage by -0.14% ⚠️

Coverage data is based on head (b284cf2) compared to base (1a485f7).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5597      +/-   ##
==========================================
- Coverage   75.67%   75.52%   -0.15%     
==========================================
  Files         326      326              
  Lines       32370    32370              
==========================================
- Hits        24495    24449      -46     
- Misses       5767     5809      +42     
- Partials     2108     2112       +4     

Flag	Coverage Δ
unittests	75.52% <100.00%> (-0.15%)	⬇️

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

Impacted Files	Coverage Δ
server/statistics/store_load.go	98.01% <100.00%> (ø)
pkg/errs/errs.go	75.00% <0.00%> (-25.00%)	⬇️
server/api/diagnostic.go	76.92% <0.00%> (-23.08%)	⬇️
pkg/tempurl/tempurl.go	45.00% <0.00%> (-15.00%)	⬇️
server/schedulers/shuffle_hot_region.go	56.00% <0.00%> (-10.00%)	⬇️
server/id/id.go	83.05% <0.00%> (-6.78%)	⬇️
server/schedulers/hot_region_v2.go	73.09% <0.00%> (-6.44%)	⬇️
server/storage/kv/etcd_kv.go	79.71% <0.00%> (-5.80%)	⬇️
server/cluster/diagnostic_manager.go	72.04% <0.00%> (-4.31%)	⬇️
pkg/dashboard/adapter/manager.go	79.31% <0.00%> (-2.30%)	⬇️
... and 25 more

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.

[nolouch]

lgtm, need a test

[lhy1024]

/merge

[ti-chi-bot]

@lhy1024: 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: b284cf2

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #5617.

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #5618.

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #5619.

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #5620.

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #5621.