MdeModulePkg Variable: Make sure no more than one Variable HOB
VariableHob may be built in PcdPeim (by PcdNvStoreDefaultValueBuffer)
or some platform module (by some tool).
The two solutions should not be co-exist.
Cc: Liming Gao <liming.gao@intel.com> Cc: Jiewen Yao <jiewen.yao@intel.com> Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Star Zeng <star.zeng@intel.com> Reviewed-by: Liming Gao <liming.gao@intel.com>