There is no asynchronous operations to the registered RAM disks link list
maintained within RamDiskDxe driver, therefore, the TPL raise and restore
operations when dealing with the link list are unnecessary.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>