iio: ad7292: Prevent regulator double disable

The ad7292 tries to add an devm_action for disabling a regulator at
device detach using devm_add_action_or_reset(). The
devm_add_action_or_reset() does call the release function should adding
action fail. The driver inspects the value returned by
devm_add_action_or_reset() and manually calls regulator_disable() if
adding the action has failed. This leads to double disable and messes
the enable count for regulator.

Do not manually call disable if devm_add_action_or_reset() fails.

Fixes: 506d2e31

 ("iio: adc: Add driver support for AD7292")
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Tested-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/Yv9O+9sxU7gAv3vM@fedora


Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>