firewire: core: use guard macro to maintain list of events for userspace clients

The core function maintains events to userspace by list in the instance of
client. The concurrent access to the list is protected by spinlock in
the instance.

This commit uses guard macro to maintain the spinlock.

Link: https://lore.kernel.org/r/20240805085408.251763-10-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

drivers/firewire/core-cdev.c

@@ -287,19 +287,17 @@ static int fw_device_op_open(struct inode *inode, struct file *file)
 static void queue_event(struct client *client, struct event *event,
 			void *data0, size_t size0, void *data1, size_t size1)
 {
-	unsigned long flags;
-
 	event->v[0].data = data0;
 	event->v[0].size = size0;
 	event->v[1].data = data1;
 	event->v[1].size = size1;
 
-	spin_lock_irqsave(&client->lock, flags);
+	scoped_guard(spinlock_irqsave, &client->lock) {
 		if (client->in_shutdown)
 			kfree(event);
 		else
 			list_add_tail(&event->link, &client->event_list);
-	spin_unlock_irqrestore(&client->lock, flags);
+	}
 
 	wake_up_interruptible(&client->wait);
 }
@@ -321,10 +319,10 @@ static int dequeue_event(struct client *client,
 		       fw_device_is_shutdown(client->device))
 		return -ENODEV;
 
-	spin_lock_irq(&client->lock);
+	scoped_guard(spinlock_irq, &client->lock) {
 		event = list_first_entry(&client->event_list, struct event, link);
 		list_del(&event->link);
-	spin_unlock_irq(&client->lock);
+	}
 
 	total = 0;
 	for (i = 0; i < ARRAY_SIZE(event->v) && total < count; i++) {
@@ -1887,9 +1885,8 @@ static int fw_device_op_release(struct inode *inode, struct file *file)
 		fw_iso_buffer_destroy(&client->buffer, client->device->card);
 
 	/* Freeze client->resource_idr and client->event_list */
-	spin_lock_irq(&client->lock);
+	scoped_guard(spinlock_irq, &client->lock)
 		client->in_shutdown = true;
-	spin_unlock_irq(&client->lock);
 
 	wait_event(client->tx_flush_wait, !has_outbound_transactions(client));