hwmon: (lm83) fix checkpatch issues

resolved:
ERROR: trailing whitespace
WARNING: please, no spaces at the start of a line
WARNING: simple_strtol is obsolete, use kstrtol instead
ERROR: do not use assignment in if condition

Signed-off-by: Frans Meulenbroeks <fransmeulenbroeks@gmail.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>