fix(system_monitor): fix unreadVariable

[kobayu858]

Description

This is a fix based on cppcheck unreadVariable warnings.

system/system_monitor/src/cpu_monitor/intel_cpu_monitor.cpp:133:13: style: Variable 'level' is assigned a value that is never used. [unreadVariable]
  int level = DiagStatus::OK;
            ^

system/system_monitor/src/gpu_monitor/nvml_gpu_monitor.cpp:133:13: style: Variable 'level' is assigned a value that is never used. [unreadVariable]
  int level = DiagStatus::OK;
            ^

system/system_monitor/src/gpu_monitor/nvml_gpu_monitor.cpp:267:13: style: Variable 'level' is assigned a value that is never used. [unreadVariable]
  int level = DiagStatus::OK;
            ^

Related links

Parent Issue:

• Link

How was this PR tested?

Notes for reviewers

None.

Interface changes

None.

Effects on system behavior

None.

[github-actions]

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[ito-san]

LGTM

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 0.00%. Comparing base (a5d77b4) to head (99afd60).
Report is 11 commits behind head on main.

Files	Patch %	Lines
...stem_monitor/src/cpu_monitor/intel_cpu_monitor.cpp	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #8372       +/-   ##
==========================================
- Coverage   23.73%   0.00%   -23.74%     
==========================================
  Files        1378      46     -1332     
  Lines      101354    2985    -98369     
  Branches    38503     456    -38047     
==========================================
- Hits        24057       0    -24057     
+ Misses      74828    2985    -71843     
+ Partials     2469       0     -2469     

Flag	Coverage Δ
differential	0.00% <0.00%> (?)
total	?

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