ACPI: fix a section mismatch

WARNING: drivers/acpi/acpi.o(.text+0xeda): Section mismatch in reference from the function acpi_os_initialize1() to the function .init.text:set_osi_linux()

The function acpi_os_initialize1() references
the function __init set_osi_linux().

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 966fedd..f7227e9 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -1530,7 +1530,7 @@
 	return AE_OK;
 }
 
-acpi_status acpi_os_initialize1(void)
+acpi_status __init acpi_os_initialize1(void)
 {
 	kacpid_wq = create_workqueue("kacpid");
 	kacpi_notify_wq = create_workqueue("kacpi_notify");