Since "uint8_t page[CPU_PAGE_SIZE]" wants to ensure the first_page only
took PAGE_SIZE memory space and aligned to PAGE_SIZE. However, it couldn't.
So just make it simpler.
Tracked-On: #861
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
Reviewed-by: Qi, Yadong <yadong.qi@intel.com>