hwmon: (pwm-fan) Update the duty cycle inorder to control the pwm-fan

pwm_config() must be called with a duty cycle of 0 prior to calling
pwm_disable() to ensure that the pwm signal is set to low.

Reported-by: Markus Reichl <[e-mail]>
Tested-by: Markus Reichl <[e-mail]>
Reviewed-by: Lukasz Majewski <[e-mail]>
Reviewed-by: Sjoerd Simons <[e-mail]>
Signed-off-by: Anand Moon <[e-mail]>
Signed-off-by: Guenter Roeck <[e-mail]>

drivers/hwmon/pwm-fan.c

···
 	if (ctx->pwm_value == pwm)
 		goto exit_set_pwm_err;
 
-	if (pwm == 0) {
-		pwm_disable(ctx->pwm);
-		goto exit_set_pwm;
-	}
-
 	duty = DIV_ROUND_UP(pwm * (ctx->pwm->period - 1), MAX_PWM);
 	ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
 	if (ret)
 		goto exit_set_pwm_err;
+
+	if (pwm == 0)
+		pwm_disable(ctx->pwm);
 
 	if (ctx->pwm_value == 0) {
 		ret = pwm_enable(ctx->pwm);
···
 			goto exit_set_pwm_err;
 	}
 
-exit_set_pwm:
 	ctx->pwm_value = pwm;
 exit_set_pwm_err:
 	mutex_unlock(&ctx->lock);