iio: light: apds9960: silence uninitialized variable warning

It causes a static checker warning if we use "buf" on the failure path
so move that inside the if statement.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/light/apds9960.c b/drivers/iio/light/apds9960.c
index 47fcd5a..35928fb 100644
--- a/drivers/iio/light/apds9960.c
+++ b/drivers/iio/light/apds9960.c
@@ -495,9 +495,10 @@
 		case IIO_INTENSITY:
 			ret = regmap_bulk_read(data->regmap, chan->address,
 					       &buf, 2);
-			if (!ret)
+			if (!ret) {
 				ret = IIO_VAL_INT;
-			*val = le16_to_cpu(buf);
+				*val = le16_to_cpu(buf);
+			}
 			break;
 		default:
 			ret = -EINVAL;