iio: Don't use bare "unsigned"

Use "unsigned int" rather than bare "unsigned". Reported by checkpatch.pl.

Signed-off-by: Joe Simmons-Talbott <joetalbott@gmail.com>
Link: https://lore.kernel.org/r/20220624021806.1010962-1-joetalbott@gmail.com


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