ACPI: use more understandable bus_id for ACPI devices

Some of the ACPI devices use the internal fake hids
which are exposed to userspace as devces' bus_id after sysfs conversion.
To make it more friendly, we convert them to more understandable strings.

For those devices w/o PNPids, we use "device:instance_no" as the bus_id
instead of "PNPIDNON:instance_no".

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 30a39ba..4139e65 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -26,7 +26,7 @@
 LIST_HEAD(acpi_wakeup_device_list);
 
 struct acpi_device_bus_id{
-	char bus_id[9];
+	char bus_id[15];
 	unsigned int instance_no;
 	struct list_head node;
 };
@@ -342,7 +342,7 @@
 	 * If failed, create one and link it into acpi_bus_id_list
 	 */
 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
-		if(!strcmp(acpi_device_bus_id->bus_id, device->flags.hardware_id? device->pnp.hardware_id : "PNPIDNON")) {
+		if(!strcmp(acpi_device_bus_id->bus_id, device->flags.hardware_id? device->pnp.hardware_id : "device")) {
 			acpi_device_bus_id->instance_no ++;
 			found = 1;
 			kfree(new_bus_id);
@@ -351,7 +351,7 @@
 	}
 	if(!found) {
 		acpi_device_bus_id = new_bus_id;
-		strcpy(acpi_device_bus_id->bus_id, device->flags.hardware_id ? device->pnp.hardware_id : "PNPIDNON");
+		strcpy(acpi_device_bus_id->bus_id, device->flags.hardware_id ? device->pnp.hardware_id : "device");
 		acpi_device_bus_id->instance_no = 0;
 		list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
 	}