[Minor] Check the result of listHosts()

[Aiee]

What type of PR is this?

• bug
• feature
• enhancement

What does this PR do?

Check the result of listHosts(). Currently, the result of listHosts() is never checked.

Which issue(s)/PR(s) this PR relates to?

Special notes for your reviewer, ex. impact of this fix, etc:

Additional context:

Checklist：

• Documentation affected （Please add the label if documentation needs to be modified.)
• Incompatible （If it is incompatible, please describe it and add corresponding label.）
• Need to cherry-pick （If need to cherry-pick to some branches, please label the destination version(s).)
• Performance impacted: Consumes more CPU/Memory

Release notes：

Please confirm whether to reflect in release notes and how to describe:

[codecov-commenter]

Codecov Report

Merging #3382 (641d0f2) into master (fe68b0e) will decrease coverage by 0.00%.
The diff coverage is 76.92%.

@@            Coverage Diff             @@
##           master    #3382      +/-   ##
==========================================
- Coverage   85.27%   85.27%   -0.01%     
==========================================
  Files        1276     1276              
  Lines      118999   118997       -2     
==========================================
- Hits       101475   101472       -3     
- Misses      17524    17525       +1     

Impacted Files	Coverage Δ
src/common/expression/ContainerExpression.cpp	90.00% <66.66%> (-2.13%)	⬇️
src/clients/meta/MetaClient.cpp	75.62% <100.00%> (-0.42%)	⬇️
src/graph/validator/test/YieldValidatorTest.cpp	91.78% <100.00%> (ø)
src/parser/test/ParserTest.cpp	100.00% <100.00%> (ø)
src/meta/processors/parts/GetSpaceProcessor.cpp	60.60% <0.00%> (-18.19%)	⬇️
src/meta/processors/BaseProcessor.h	75.67% <0.00%> (-16.22%)	⬇️
src/common/thrift/ThriftClientManager-inl.h	82.97% <0.00%> (-6.39%)	⬇️
src/common/datatypes/HostAddrOps-inl.h	75.67% <0.00%> (-2.71%)	⬇️
src/common/base/Status.h	88.63% <0.00%> (-2.28%)	⬇️
src/common/expression/LogicalExpression.cpp	91.66% <0.00%> (-1.73%)	⬇️
... and 33 more

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