Fix compiler warnings with ENABLE_WARNINGS=ON

[masterleinad]

Description

Fixes the warnings I am seeing with ENABLE_WARNINGS=ON on ALCF's sunspot testbed.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature/architecture support (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Build/CI update

How Has This Been Tested?

Compiling and testing on ALCF's sunspot testbed.

Checklist:

• I have run ./scripts/check-code-format.sh and confirm my code code follows the style guidelines of variorum
• I have added comments in my code
• My changes generate no new warnings (build with -DENABLE_WARNINGS=ON)
• New and existing unit tests pass with my changes

Thank you for taking the time to contribute to Variorum!

[tpatki]

Hi @masterleinad! Thank you so much for testing on sunspot for us! This is very helpful.

Could you tell me what the warning with the tid part was? I am assuming the ret warning was around uninitialized variables. It'll be good to document the warnings you were seeing in the PR, so we know what was fixed if we ever needed to revisit it.

[masterleinad]

Could you tell me what the warning with the tid part was? I am assuming the ret warning was around uninitialized variables. It'll be good to document the warnings you were seeing in the PR, so we know what was fixed if we ever needed to revisit it.

/home/darndt/variorum/src/examples/openmp-examples/variorum-print-verbose-power-openmp-example.c:61:13: error: variable 'ret' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
   61 |         if (tid == 0)
      |             ^~~~~~~~
/home/darndt/variorum/src/examples/openmp-examples/variorum-print-verbose-power-openmp-example.c:82:12: note: uninitialized use occurs here
   82 |     return ret;
      |            ^~~
/home/darndt/variorum/src/examples/openmp-examples/variorum-print-verbose-power-openmp-example.c:61:9: note: remove the 'if' if its condition is always true
   61 |         if (tid == 0)
      |         ^~~~~~~~~~~~~
   62 |         {
/home/darndt/variorum/src/examples/openmp-examples/variorum-print-verbose-power-openmp-example.c:29:12: note: initialize the variable 'ret' to silence this warning
   29 |     int ret;
      |            ^
      |             = 0

I guess the tid part is not really necessary but it's not used outside the OpenMP parallel region.

[tpatki]

Thanks for documenting the errors. Merging.