CorebootPayloadPkg PlatformHookLib: Fix GCC build failure

CorebootPayloadPkg PlatformHookLib: Fix GCC build failure

Add return status check to fix GCC build failure below.

error: right-hand operand of comma expression has no effect
[-Werror=unused-value]
((_gPcd_BinaryPatch_PcdSerialUseMmio = (Value)), RETURN_SUCCESS)

error: right-hand operand of comma expression has no effect
[-Werror=unused-value]
((_gPcd_BinaryPatch_PcdSerialRegisterBase = (Value)), RETURN_SUCCESS)

http://article.gmane.org/gmane.comp.bios.edk2.devel/4949

Cc: Maurice Ma <maurice.ma@intel.com>
Cc: Prince Agyeman <prince.agyeman@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Suggested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Maurice Ma <maurice.ma@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19069 6f19259b-4bc3-4df7-8a09-765794883524