hwmon: (pc87427) Move sysfs file removal to a separate function

The sysfs file removal code is the same in the probe error path and in
the remove function, so move it to a separate function to avoid code
duplication.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>