ACPI: AC: Remove redundant checks

Remove unnecessary checks against NULL for pointers that can't be NULL
when the checks are done.

Signed-off-by: Michal Wilczynski <michal.wilczynski@intel.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: mwilczy

drivers/acpi/ac.c

@@ -131,9 +131,6 @@ static void acpi_ac_notify(acpi_handle handle, u32 event, void *data)
 	struct acpi_device *device = data;
 	struct acpi_ac *ac = acpi_driver_data(device);
 
-	if (!ac)
-		return;
-
 	switch (event) {
 	default:
 		acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
@@ -216,12 +213,8 @@ static const struct dmi_system_id ac_dmi_table[]  __initconst = {
 static int acpi_ac_add(struct acpi_device *device)
 {
 	struct power_supply_config psy_cfg = {};
-	int result = 0;
-	struct acpi_ac *ac = NULL;
-
-
-	if (!device)
-		return -EINVAL;
+	struct acpi_ac *ac;
+	int result;
 
 	ac = kzalloc(sizeof(struct acpi_ac), GFP_KERNEL);
 	if (!ac)
@@ -275,16 +268,9 @@ static int acpi_ac_add(struct acpi_device *device)
 #ifdef CONFIG_PM_SLEEP
 static int acpi_ac_resume(struct device *dev)
 {
-	struct acpi_ac *ac;
+	struct acpi_ac *ac = acpi_driver_data(to_acpi_device(dev));
 	unsigned int old_state;
 
-	if (!dev)
-		return -EINVAL;
-
-	ac = acpi_driver_data(to_acpi_device(dev));
-	if (!ac)
-		return -EINVAL;
-
 	old_state = ac->state;
 	if (acpi_ac_get_state(ac))
 		return 0;
@@ -299,12 +285,7 @@ static int acpi_ac_resume(struct device *dev)
 
 static void acpi_ac_remove(struct acpi_device *device)
 {
-	struct acpi_ac *ac = NULL;
-
-	if (!device || !acpi_driver_data(device))
-		return;
-
-	ac = acpi_driver_data(device);
+	struct acpi_ac *ac = acpi_driver_data(device);
 
 	acpi_dev_remove_notify_handler(device, ACPI_ALL_NOTIFY,
 				       acpi_ac_notify);