iio: accel: sca3000: use devm_iio_kfifo_buffer_setup() helper

This change makes use of the devm_iio_kfifo_buffer_setup() helper, however
the unwind order is changed.
The life-time of the kfifo object is attached to the parent device object.
This is to make the driver a bit more consistent with the other IIO
drivers, even though (as it is now before this change) it shouldn't be a
problem.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-5-alexandru.ardelean@analog.com


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