x86: early_ioremap_reset fix 2

This patch fixes a bug of early_ioremap_reset(), which had been fixed
before by "convert the boot time page table to the kernels native
format" patch. But that patch has been reverted now.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>