hwmon: (applesmc) Fix checkpatch errors and fix value range checks

This patch fixes all checkpatch errors and most of the checkpatch warnings.
It also fixes the range check in applesmc_store_fan_speed().

Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Acked-by: Henrik Rydberg <rydberg@euromail.se>