drivers: iio: max1027: Fix sparse warning: "dubious: x | !y"

Fixing below warning:
drivers/iio/adc/max1027.c:241:34: warning: dubious: x | !y .
Signed-off-by: Sandhya Bankar <bankarsandhya512@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/adc/max1027.c

@@ -238,7 +238,9 @@ static int max1027_read_single_value(struct iio_dev *indio_dev,
 
 	/* Configure conversion register with the requested chan */
 	st->reg = MAX1027_CONV_REG | MAX1027_CHAN(chan->channel) |
-		  MAX1027_NOSCAN | !!(chan->type == IIO_TEMP);
+		  MAX1027_NOSCAN;
+	if (chan->type == IIO_TEMP)
+		st->reg |= MAX1027_TEMP;
 	ret = spi_write(st->spi, &st->reg, 1);
 	if (ret < 0) {
 		dev_err(&indio_dev->dev,