etcdutil: only output the log when picked count > 0

[JmPotato]

What problem does this PR solve?

Issue Number: close #7844.

What is changed and how does it work?

Only output the log when picked count > 0 in `updateEvictedEps`.

Check List

Tests

• Unit test
• Integration test

Release note

None.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• rleungx

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[codecov]

Codecov Report

Merging #7845 (343337c) into master (d6d9fea) will decrease coverage by 0.08%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #7845      +/-   ##
==========================================
- Coverage   73.51%   73.44%   -0.08%     
==========================================
  Files         432      432              
  Lines       47913    47915       +2     
==========================================
- Hits        35225    35189      -36     
- Misses       9642     9671      +29     
- Partials     3046     3055       +9     

Flag	Coverage Δ
unittests	73.44% <100.00%> (-0.08%)	⬇️

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[JmPotato]

/merge

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[ti-chi-bot]

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

Commit hash: 343337c

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.5: #7977.