iio: light: noa1305: Simplify noa1305_read_raw()

The only channel this hardware supports is IIO_LIGHT, if the channel
is anything else, exit right away. The 'ret' variable is now always
only assigned by noa1305_measure(), do not initialize it anymore.
Update function parameter indent. No functional change.

Signed-off-by: Marek Vasut <marex@denx.de>
Link: https://patch.msgid.link/20240715183120.143417-1-marex@denx.de


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