The serial interface can be reset by writing 32 consecutive 1s to the device.
'ret' was initialized correctly but its value was overwritten when
ad7793_check_platform_data() was called. Since a dedicated reset function
is present now, it should be used instead.
Fixes: 2edb769d246e ("iio:ad7793: Add support for the ad7798 and ad7799") Signed-off-by: Dragos Bogdan <dragos.bogdan@analog.com> Acked-by: Lars-Peter Clausen <lars@metafoo.de> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>