iio: imu: adis: Add a missing '\n' in a log message

Message logged by 'dev_xxx()' or 'pr_xxx()' should end with a '\n'.

Fixes: 1fd45670 ("iio: imu: adis: add support product ID check in adis_initial_startup")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>