OvmfPkg/BaseMemEncryptTdxLib: fix variable uninitialized error

[t0rr3sp3dr0]

Description

While compiling the project, I was getting the error bellow. Whenever Mode wasn't ClearSharedBit, the Status variable was uninitialized but being used by the DEBUG call. This patch initializes Status with EFI_SUCCESS to address the problem.

./OvmfPkg/Library/BaseMemEncryptTdxLib/MemoryEncryption.c:592:7: error: variable 'Status' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
  if (Mode == ClearSharedBit) {
      ^~~~~~~~~~~~~~~~~~~~~~
./OvmfPkg/Library/BaseMemEncryptTdxLib/MemoryEncryption.c:616:5: note: uninitialized use occurs here
    Status
    ^~~~~~
./MdePkg/Include/Library/DebugLib.h:425:24: note: expanded from macro 'DEBUG'
      _DEBUGLIB_DEBUG (Expression);       \
                       ^~~~~~~~~~
./MdePkg/Include/Library/DebugLib.h:378:49: note: expanded from macro '_DEBUGLIB_DEBUG'
#define _DEBUGLIB_DEBUG(Expression)  DebugPrint Expression
                                                ^~~~~~~~~~
./OvmfPkg/Library/BaseMemEncryptTdxLib/MemoryEncryption.c:592:3: note: remove the 'if' if its condition is always true
  if (Mode == ClearSharedBit) {
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
./OvmfPkg/Library/BaseMemEncryptTdxLib/MemoryEncryption.c:529:39: note: initialize the variable 'Status' to silence this warning
  EFI_STATUS                    Status;
                                      ^
                                       = 0

• 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

Compiled the project again.

Integration Instructions

N/A

[t0rr3sp3dr0]

I think this was never caught before because the project needs to be compiled with DEBUG_VERBOSE for the error to show up.

[t0rr3sp3dr0]

Just updated the commit message to include the patch description

[jyao1]

Shouldn't we just remove status from the DEBUG message?

According to the logic, I feel the Status can only be SUCCESS. It seems not meaningful to dump it.