MdeModulePkg/HiiDatabaseDxe: Remove efivarstore check for string load…

[poloaegis83]

Description

Remove efivarstore IFR buffer check when string load default. In the case of varstore type IFR, it will be NULL.

• Breaking change?
  • Breaking change - Does this PR cause a break in build or boot behavior?
  • Examples: Does it add a new library class or move a module to a different repo.
• Impacts security?
  • Security - Does this PR have a direct security impact?
  • Examples: Crypto algorithm change or buffer overflow fix.
• Includes tests?
  • Tests - Does this PR include any explicit test code?
  • Examples: Unit tests or integration tests.

How This Was Tested

1. Boot to both VarStore and EfiVarStore type IFR setup pages,
   check string load default function works for EfiVarStore type IFR pages.
2. Entering every formset , should be load success without ASSERT.

Integration Instructions

N/A

[lgao4]

This PR fixes the issue introduced by #10568. Because #10568 has been merged, this PR will be required to be merged for this stable tag 202502.

[lgao4]

@mdkinney , @makubacki , @ardbiesheuvel , @leiflindholm , I suggest to merge this fix for stable tag 202502.

[makubacki]

Including the commit that introduced the issue (cbe8a09) in this commit's message would be nice to more directly allow the issue to be tracked in history.

[poloaegis83]

Including the commit that introduced the issue (cbe8a09) in this commit's message would be nice to more directly allow the issue to be tracked in history.

Add issue(cbe8a09) description in commit message.