iio: adc: sc27xx: Replace devm_add_action() followed by failure action with devm_add_action_or_reset()

devm_add_action_or_reset() is introduced as a helper function which
internally calls devm_add_action(). If devm_add_action() fails
then it will execute the action mentioned and return the error code.
This reduce source code size (avoid writing the action twice)
and reduce the likelyhood of bugs.
Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>