media: v4l: async: Correctly serialise async sub-device unregistration

The check whether an async sub-device is bound to a notifier was performed
without list_lock held, making it possible for another process to
unbind the async sub-device before the sub-device unregistration function
proceeds to take the lock.

Fix this by first acquiring the lock and then proceeding with the check.

Signed-off-by: Sakari Ailus <[email protected]>
Reviewed-by: Sebastian Reichel <[email protected]>
Acked-by: Hans Verkuil <[email protected]>
Acked-by: Niklas Söderlund <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>

0 files changed, 0 insertions, 0 deletions