x86: always explicitly map acpi memory

Always map acpi tables, rather than assuming we can use the normal
linear mapping to access the acpi tables.  This is necessary in a
virtual environment where the linear mappings are to pseudo-physical
memory, but the acpi tables exist at a real physical address.  It
doesn't hurt to map in the normal non-virtual case, so just do it
unconditionally.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/acpi/boot.c

@@ -127,9 +127,6 @@ char *__init __acpi_map_table(unsigned long phys, unsigned long size)
 	if (!phys || !size)
 		return NULL;
 
-	if (phys+size <= (max_low_pfn_mapped << PAGE_SHIFT))
-		return __va(phys);
-
 	if (prev_map)
 		early_iounmap(prev_map, prev_size);