iio: imu: adis16480: Use temporary variable for struct device

Use temporary variable for struct device to make code neater.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Tested-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220414131559.24694-2-andriy.shevchenko@linux.intel.com


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