MdeModulePkg: PCD/Pei: eliminate unused but set variable

MdeModulePkg: PCD/Pei: eliminate unused but set variable

- SVN r14866:

  MdePkg and MdeModulePkg Pcd: Add the new EFI_GET_PCD_INFO_PROTOCOL and
  EFI_GET_PCD_INFO_PPI support for PI 1.2.1 compliance.

added the "DataBase" local variable to PcdPeimInit(), and both set it and
used it.

- SVN r14869:

  MdeModulePkg and Nt32Pkg Pcd: Add the new EFI_GET_PCD_INFO_PROTOCOL and
  EFI_GET_PCD_INFO_PPI support for PI 1.2.1  compliance.

changed the PcdPeimInit() function, but "DataBase" remained both set and
used.

- SVN r17173:

  MdeModulePkg Pcd: Check the input SkuId in SetSku()

changed the function again; and this time "DataBase" became
set-but-unused. It triggers the following build error, when building
ArmVirtualizationQemu.dsc with gcc-4.8:

  MdeModulePkg/Universal/PCD/Pei/Pcd.c:150:21: error: variable 'DataBase'
  set but not used [-Werror=unused-but-set-variable]
     PEI_PCD_DATABASE  *DataBase;
                       ^
  cc1: all warnings being treated as errors

Fix the error by removing the DataBase variable, restoring the pre-r14866
state locally, when the BuildPcdDatabase() function was called, but its
return value was thrown away.

Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17179 6f19259b-4bc3-4df7-8a09-765794883524