thermal/drivers/qcom: Fix error code in adc_tm5_get_dt_channel_data()

Return -EINVAL when args is invalid instead of 'ret' which is set to
zero by a previous successful call to a function.

Fixes: ca66dca5 ("thermal: qcom: add support for adc-tm5 PMIC thermal monitor")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210527092640.2070555-1-yangyingliang@huawei.com

drivers/thermal/qcom/qcom-spmi-adc-tm5.c

@@ -441,7 +441,7 @@ static int adc_tm5_get_dt_channel_data(struct adc_tm5_chip *adc_tm,
 
 	if (args.args_count != 1 || args.args[0] >= ADC5_MAX_CHANNEL) {
 		dev_err(dev, "%s: invalid ADC channel number %d\n", name, chan);
-		return ret;
+		return -EINVAL;
 	}
 	channel->adc_channel = args.args[0];