Input: psmouse-smbus - use guard notation when acquiring mutex

This makes the code more compact and error handling more robust
by ensuring that mutexes are released in all code paths when control
leaves critical section.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/mouse/psmouse-smbus.c

···
 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HOST_NOTIFY))
 		return;
 
-	mutex_lock(&psmouse_smbus_mutex);
+	guard(mutex)(&psmouse_smbus_mutex);
 
 	list_for_each_entry(smbdev, &psmouse_smbus_list, node) {
 		if (smbdev->dead)
···
 			    "SMBus candidate adapter appeared, triggering rescan\n");
 		serio_rescan(smbdev->psmouse->ps2dev.serio);
 	}
-
-	mutex_unlock(&psmouse_smbus_mutex);
 }
 
 static void psmouse_smbus_detach_i2c_client(struct i2c_client *client)
 {
 	struct psmouse_smbus_dev *smbdev, *tmp;
 
-	mutex_lock(&psmouse_smbus_mutex);
+	guard(mutex)(&psmouse_smbus_mutex);
 
 	list_for_each_entry_safe(smbdev, tmp, &psmouse_smbus_list, node) {
 		if (smbdev->client != client)
···
 			kfree(smbdev);
 		}
 	}
-
-	mutex_unlock(&psmouse_smbus_mutex);
 }
 
 static int psmouse_smbus_notifier_call(struct notifier_block *nb,
···
 {
 	struct psmouse_smbus_dev *smbdev = psmouse->private;
 
-	mutex_lock(&psmouse_smbus_mutex);
+	guard(mutex)(&psmouse_smbus_mutex);
 
 	if (smbdev->dead) {
 		list_del(&smbdev->node);
···
 			    dev_name(&smbdev->client->dev));
 		psmouse_smbus_schedule_remove(smbdev->client);
 	}
-
-	mutex_unlock(&psmouse_smbus_mutex);
 
 	psmouse->private = NULL;
 }
···
 {
 	struct psmouse_smbus_dev *smbdev, *tmp;
 
-	mutex_lock(&psmouse_smbus_mutex);
+	guard(mutex)(&psmouse_smbus_mutex);
 
 	list_for_each_entry_safe(smbdev, tmp, &psmouse_smbus_list, node) {
 		if (psmouse == smbdev->psmouse) {
···
 			kfree(smbdev);
 		}
 	}
-
-	mutex_unlock(&psmouse_smbus_mutex);
 }
 
 int psmouse_smbus_init(struct psmouse *psmouse,
···
 	psmouse->disconnect = psmouse_smbus_disconnect;
 	psmouse->resync_time = 0;
 
-	mutex_lock(&psmouse_smbus_mutex);
-	list_add_tail(&smbdev->node, &psmouse_smbus_list);
-	mutex_unlock(&psmouse_smbus_mutex);
+	scoped_guard(mutex, &psmouse_smbus_mutex) {
+		list_add_tail(&smbdev->node, &psmouse_smbus_list);
+	}
 
 	/* Bind to already existing adapters right away */
 	error = i2c_for_each_dev(smbdev, psmouse_smbus_create_companion);
···
 	smbdev->board.platform_data = NULL;
 
 	if (error < 0 || !leave_breadcrumbs) {
-		mutex_lock(&psmouse_smbus_mutex);
-		list_del(&smbdev->node);
-		mutex_unlock(&psmouse_smbus_mutex);
+		scoped_guard(mutex, &psmouse_smbus_mutex) {
+			list_del(&smbdev->node);
+		}
 
 		kfree(smbdev);
 	}