hwmon: Avoid initializing the same field twice

hwmon: Avoid initializing the same field twice

All hwmon drivers allocate their data structure with some form of
kzalloc, so setting data fields to zero explicitly is a waste of time.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>