ACPI / memhotplug: bind the memory device when the driver is being loaded

We had introduced acpi_hotmem_initialized to avoid strange add_memory fail
message.  But the memory device may not be used by the kernel, and the
device should be bound when the driver is being loaded.  Remove
acpi_hotmem_initialized to allow that the device can be bound when the
driver is being loaded.
Signed-off-by: NWen Congyang <wency@cn.fujitsu.com>
Reviewed-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpi_memhotplug.c

@@ -87,8 +87,6 @@ struct acpi_memory_device {
 	struct list_head res_list;
 };
 
-static int acpi_hotmem_initialized;
-
 static acpi_status
 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
 {
@@ -433,15 +431,6 @@ static int acpi_memory_device_add(struct acpi_device *device)
 
 	printk(KERN_DEBUG "%s \n", acpi_device_name(device));
 
-	/*
-	 * Early boot code has recognized memory area by EFI/E820.
-	 * If DSDT shows these memory devices on boot, hotplug is not necessary
-	 * for them. So, it just returns until completion of this driver's
-	 * start up.
-	 */
-	if (!acpi_hotmem_initialized)
-		return 0;
-
 	if (!acpi_memory_check_device(mem_device)) {
 		/* call add_memory func */
 		result = acpi_memory_enable_device(mem_device);
@@ -557,7 +546,6 @@ static int __init acpi_memory_device_init(void)
 		return -ENODEV;
 	}
 
-	acpi_hotmem_initialized = 1;
 	return 0;
 }