Various fixes caught by CLANG

[kuqin12]

Preface

Please ensure you have read the contribution docs prior to submitting the pull request. In particular, pull request guidelines.

Description

This change will cover a few more CLANG fixes, including uninitialized variables and unintentionally pulled in compiler intrinsics.

For each item, place an "x" in between [ and ] if true. Example: [x]. (you can also check items in the GitHub UI)

• [x] Impacts functionality?
  • Functionality - Does the change ultimately impact how firmware functions?
  • Examples: Add a new library, publish a new PPI, update an algorithm, ...
• [ ] Impacts security?
  • Security - Does the change have a direct security impact on an application, flow, or firmware?
  • Examples: Crypto algorithm change, buffer overflow fix, parameter validation improvement, ...
• [ ] Breaking change?
  • Breaking change - Will anyone consuming this change experience a break in build or boot behavior?
  • Examples: Add a new library class, move a module to a different repo, call a function in a new library class in a pre-existing module, ...
• [ ] Includes tests?
  • Tests - Does the change include any explicit test code?
  • Examples: Unit tests, integration tests, robot tests, ...
• [ ] Includes documentation?
  • Documentation - Does the change contain explicit documentation additions outside direct code modifications (and comments)?
  • Examples: Update readme file, add feature readme file, link to documentation on an a separate Web page, ...

How This Was Tested

This was tested on QEMU Q35.

Integration Instructions

N/A

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.

Project coverage is 0.31%. Comparing base (548aad1) to head (0307d7b).

Files	Patch %	Lines
MmSupervisorPkg/Core/Request/UnblockMemory.c	0.00%	3 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #303 +/- ## ======================================== - Coverage 0.47% 0.31% -0.17% ======================================== Files 144 144 Lines 22079 22061 -18 Branches 60 60 ======================================== - Hits 105 69 -36 + Misses 21969 21965 -4 - Partials 5 27 +22 ``` | [Flag](https://app.codecov.io/gh/microsoft/mu_feature_mm_supv/pull/303/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=microsoft) | Coverage Δ | | |---|---|---| | [MmSupervisorPkg](https://app.codecov.io/gh/microsoft/mu_feature_mm_supv/pull/303/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=microsoft) | `0.31% <0.00%> (-0.17%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=microsoft#carryforward-flags-in-the-pull-request-comment) to find out more.

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