iio: adc: ad7292: Modify the bool initialization assignment

A bool initializer is best assigned to false rather than 0.

Signed-off-by: Guoqing Chi <chiguoqing@yulong.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/20210319062706.5135-1-chi962464zy@163.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>