iio: accel: adxl355: use if(ret) in place of ret < 0

Replace if(ret < 0) with if(ret) for consistency.

Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Link: https://lore.kernel.org/r/20210903184312.21009-2-puranjay12@gmail.com


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