Staging:iio:adc:ad7606: Match parenthesis alignment

Change close parenthesis alignment to match respective open parenthesis at
iio/drivers/staging/iio/adc/ad7606.c line 379.
This makes the file more compliant with the preferred coding style for the
linux kernel.

Signed-of-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>