x86: fix section mismatch warning in acpi/boot.c

Fix following warning:
WARNING: o-x86_64/arch/x86/kernel/built-in.o(.text+0x13d15): Section mismatch in reference from the function acpi_map_lsapic() to the function .cpuinit.text:mp_register_lapic()

The function acpi_map_lsapic() is exported and thus not annotated.
But the sole user is acpi/processor_core.c in a __cpuinit path.
So create a small wrapper and put back the annotation thus
avoiding the warning.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/acpi/boot.c

@@ -496,7 +496,8 @@ EXPORT_SYMBOL(acpi_register_gsi);
  *  ACPI based hotplug support for CPU
  */
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
-int acpi_map_lsapic(acpi_handle handle, int *pcpu)
+
+static int __cpuinit _acpi_map_lsapic(acpi_handle handle, int *pcpu)
 {
 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 	union acpi_object *obj;
@@ -551,6 +552,11 @@ int acpi_map_lsapic(acpi_handle handle, int *pcpu)
 	return 0;
 }
 
+/* wrapper to silence section mismatch warning */
+int __ref acpi_map_lsapic(acpi_handle handle, int *pcpu)
+{
+	return _acpi_map_lsapic(handle, pcpu);
+}
 EXPORT_SYMBOL(acpi_map_lsapic);
 
 int acpi_unmap_lsapic(int cpu)