iio: adc: max1027: fix error code in max1027_wait_eoc()

Return -ETIMEDOUT on timeout instead of success.

Fixes: 1f7b4048 ("iio: adc: max1027: Use the EOC IRQ when populated for single reads")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/max1027.c

@@ -287,7 +287,7 @@ static int max1027_wait_eoc(struct iio_dev *indio_dev)
 						  msecs_to_jiffies(1000));
 		reinit_completion(&st->complete);
 		if (!ret)
-			return ret;
+			return -ETIMEDOUT;
 	} else {
 		if (indio_dev->active_scan_mask)
 			conversion_time *= hweight32(*indio_dev->active_scan_mask);