iio: health: afe4403: Don't return an error in .remove()

The only effect of returning an error in an spi .remove() callback is
that the spi core issues another warning message. Don't report the same
problem twice and return 0 unconditionally instead. Also degrade the log
level to warning, as nothing really bad is expected from a failure to
put the device in suspend mode.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20211013203223.2694577-12-u.kleine-koenig@pengutronix.de


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