MdeModulePkg/ResetUtilityLib: Add pack(1) for reset data structure

MdeModulePkg/ResetUtilityLib: Add pack(1) for reset data structure

RESET_UTILITY_GUID_SPECIFIC_RESET_DATA structure should be declared
as pack(1).
The patch adds the missing pack(1) pragma.

(GUID *)((UINT8 *)&ResetData +
OFFSET_OF (RESET_UTILITY_GUID_SPECIFIC_RESET_DATA, ResetSubtype))
is used to replace &ResetData.ResetSubType to resolve C4366 VS
compiler warning.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>