hwmon: (w83627hf) Fix checkpatch issues

Fixed:
WARNING: simple_strtol is obsolete, use kstrtol instead
WARNING: simple_strtoul is obsolete, use kstrtoul instead
ERROR: do not use assignment in if condition

Modify multi-line comments to follow Documentation/CodingStyle.

Other checkpatch issues not fixed to reduce number of conflicts with pending
rewrite as mfd driver.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>