iio: proximity: vl53l0x: Fix return value check of wait_for_completion_timeout

wait_for_completion_timeout() returns unsigned long not int.
It returns 0 if timed out, and positive if completed.
The check for <= 0 is ambiguous and should be == 0 here
indicating timeout which is the only error case.

Fixes: 3cef2e31 ("iio: proximity: vl53l0x: Add IRQ support")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20220412064210.10734-1-linmq006@gmail.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/proximity/vl53l0x-i2c.c

@@ -104,6 +104,7 @@ static int vl53l0x_read_proximity(struct vl53l0x_data *data,
 	u16 tries = 20;
 	u8 buffer[12];
 	int ret;
+	unsigned long time_left;
 
 	ret = i2c_smbus_write_byte_data(client, VL_REG_SYSRANGE_START, 1);
 	if (ret < 0)
@@ -112,10 +113,8 @@ static int vl53l0x_read_proximity(struct vl53l0x_data *data,
 	if (data->client->irq) {
 		reinit_completion(&data->completion);
 
-		ret = wait_for_completion_timeout(&data->completion, HZ/10);
-		if (ret < 0)
-			return ret;
-		else if (ret == 0)
+		time_left = wait_for_completion_timeout(&data->completion, HZ/10);
+		if (time_left == 0)
 			return -ETIMEDOUT;
 
 		vl53l0x_clear_irq(data);