fix(sysadvisor): fix mbm calculation logic

[syc4704413]

What type of PR is this?

Bug fixes

[XudongLiuHarold]

/lgtm

might need to add some unit test cases

[codecov]

Codecov Report

❌ Patch coverage is 92.30769% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 61.90%. Comparing base (970841c) to head (7ae425e).
⚠️ Report is 30 commits behind head on main.

Files with missing lines	Patch %	Lines
...ric/provisioner/malachite/provisioner_calculate.go	92.30%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1171      +/-   ##
==========================================
+ Coverage   61.77%   61.90%   +0.13%     
==========================================
  Files         787      791       +4     
  Lines       74213    75113     +900     
==========================================
+ Hits        45843    46499     +656     
- Misses      23330    23529     +199     
- Partials     5040     5085      +45     

Flag	Coverage Δ
unittest	61.90% <92.30%> (+0.13%)	⬆️

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