block: remove outdated comments about AioContext locking
AioContext locking was removed in commit b49f4755c7 ("block: remove
AioContext locking").
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20250530151125.955508-2-f.ebner@proxmox.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>