ACPI: SBS: Fix retval warning

drivers/acpi/sbs.c: In function acpi_battery_add:
drivers/acpi/sbs.c:811: warning: ignoring return value of device_create_file,
declared with attribute warn_unused_result

Additional cleanups:
* use struct acpi_battery in acpi_battery_remove() to clean up function
calls, just like acpi_battery_add() already does.

* put braces around unregister call, as it depends on dev being not NULL.

* remove unneeded braces

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 17 insertions, 8 deletions

diff --git a/drivers/acpi/sbs.c b/drivers/acpi/sbs.c
index 90fd09c65f95..73c1ba314299 100644
--- a/drivers/acpi/sbs.c
+++ b/drivers/acpi/sbs.c
@@ -113,6 +113,7 @@ struct acpi_battery {
         u16 spec;
         u8 id;
         u8 present:1;
+        u8 have_sysfs_alarm:1;
 };
 
 #define to_acpi_battery(x) container_of(x, struct acpi_battery, bat);
@@ -808,7 +809,13 @@ static int acpi_battery_add(struct acpi_sbs *sbs, int id)
         }
         battery->bat.get_property = acpi_sbs_battery_get_property;
         result = power_supply_register(&sbs->device->dev, &battery->bat);
-        device_create_file(battery->bat.dev, &alarm_attr);
+        if (result)
+                goto end;
+        result = device_create_file(battery->bat.dev, &alarm_attr);
+        if (result)
+                goto end;
+        battery->have_sysfs_alarm = 1;
+      end:
         printk(KERN_INFO PREFIX "%s [%s]: Battery Slot [%s] (battery %s)\n",
                ACPI_SBS_DEVICE_NAME, acpi_device_bid(sbs->device),
                battery->name, sbs->battery->present ? "present" : "absent");
@@ -817,14 +824,16 @@ static int acpi_battery_add(struct acpi_sbs *sbs, int id)
 
 static void acpi_battery_remove(struct acpi_sbs *sbs, int id)
 {
-        if (sbs->battery[id].bat.dev)
-                device_remove_file(sbs->battery[id].bat.dev, &alarm_attr);
-                power_supply_unregister(&sbs->battery[id].bat);
-#ifdef CONFIG_ACPI_PROCFS
-        if (sbs->battery[id].proc_entry) {
-                acpi_sbs_remove_fs(&(sbs->battery[id].proc_entry),
-                                   acpi_battery_dir);
+        struct acpi_battery *battery = &sbs->battery[id];
+
+        if (battery->bat.dev) {
+                if (battery->have_sysfs_alarm)
+                        device_remove_file(battery->bat.dev, &alarm_attr);
+                power_supply_unregister(&battery->bat);
         }
+#ifdef CONFIG_ACPI_PROCFS
+        if (battery->proc_entry)
+                acpi_sbs_remove_fs(&battery->proc_entry, acpi_battery_dir);
 #endif
 }