Update pwm cached control registers before writing pwm enable

If pwmX_enable is written prior to displaying any attributes,
t87_update_pwm_ctrl() is never called, and the cached pwm registers
are never read before written. This results in bad values written
into various registers, and can result in operational failures.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

it87.c

@@ -1623,6 +1623,7 @@ static ssize_t set_pwm_enable(struct device *dev, struct device_attribute *attr,
 	}
 
 	mutex_lock(&data->update_lock);
+	it87_update_pwm_ctrl(data, nr);
 
 	if (val == 0) {
 		if (nr < 3 && has_fanctl_onoff(data)) {