iio:light:cm3323: add empty lines for code structure

Add some empty lines to visually separate logical structure blocks, as
after if-blocks or before regular returns.

Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Reviewed-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>