hwmon: (abituguru) Fix checkpatch issues

Fixed:
ERROR: do not use assignment in if condition
ERROR: else should follow close brace '}'
ERROR: switch and case should be at the same indent
WARNING: simple_strtoul is obsolete, use kstrtoul instead

Modify multi-line comments to follow Documentation/CodingStyle.

Not fixed:
WARNING: msleep < 20ms can sleep for up to 20ms

Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>