hwmon: (lm80) fix checkpatch messages

Fixed all checkpatch messages except
simple_strto* -> kstr*
This will be addressed in a separate patch

Also left one line-too-long message as it was only a
little bit too long and would become less readable

compile-tested: no warnings or errors

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