StandaloneMmPkg/Include/Library/FvLib: Fix section data length larger…

[apop5]

Description

This change fixed an issue where the returned section data length is always 4 bytes larger than the real section. This would cause an issue where the caller could read into the final 4 bytes which is invalid data region.

• [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 is verified on QEMU Q35 platform and booted to UEFI shell.

Integration Instructions

N/A

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

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Additional details and impacted files

@@                Coverage Diff                @@
##             release/202405     #993   +/-   ##
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  Coverage                  ?    0.20%           
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  Files                     ?      628           
  Lines                     ?   218357           
  Branches                  ?      326           
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  Hits                      ?      448           
  Misses                    ?   217900           
  Partials                  ?        9           

Flag	Coverage Δ
MdeModulePkg	0.20% <ø> (?)

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