media: stm32: dcmi: unregister notifier on probe failure

media: stm32: dcmi: unregister notifier on probe failure

dcmi_graph_init() registers the async notifier before dcmi_probe() toggles
the reset line. If reset_control_assert() or reset_control_deassert()
fails afterwards, probe returns through err_cleanup and the driver core
will not call dcmi_remove().

Unregister the notifier before cleaning it up on that error path,
matching the successful remove path and the V4L2 async notifier lifetime
rules.

Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Fixes: d079f94c9046 ("media: platform: Switch to v4l2_async_notifier_add_subdev")
Cc: stable@vger.kernel.org
[hverkuil: added Fixes tag]