Suspend notifier should only be registered and unregistered once per
hdev. Simplify this by only registering during driver registration and
simply exiting early when HCI_USER_CHANNEL is set.
Reported-by: syzbot <syzkaller@googlegroups.com> Fixes: 359ee4f834f5 (Bluetooth: Unregister suspend with userchannel) Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>