fix CONFIG_MMCONFIG=n build warning

arch/x86/kernel/acpi/boot.c:100: warning: 'acpi_mcfg_64bit_base_addr' defined
but not used

http://bugzilla.kernel.org/show_bug.cgi?id=11743

Signed-off-by: Pavel Vasilyev <linuxoid@tochka.ru>
Signed-off-by: Len Brown <len.brown@intel.com>

arch/x86/kernel/acpi/boot.c

@@ -97,7 +97,6 @@ static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE;
 #warning ACPI uses CMPXCHG, i486 and later hardware
 #endif
 
-static int acpi_mcfg_64bit_base_addr __initdata = FALSE;
 
 /* --------------------------------------------------------------------------
                               Boot-time Configuration
@@ -156,6 +155,9 @@ char *__init __acpi_map_table(unsigned long phys, unsigned long size)
 }
 
 #ifdef CONFIG_PCI_MMCONFIG
+
+static int acpi_mcfg_64bit_base_addr __initdata = FALSE;
+
 /* The physical address of the MMCONFIG aperture.  Set from ACPI tables. */
 struct acpi_mcfg_allocation *pci_mmcfg_config;
 int pci_mmcfg_config_num;