iio: imu: bno055: uninitialized variable bug in bno055_trigger_handler()

This bug is basically harmless, although it will trigger a runtime warning
if you use KMSan.  On the first iteration through the loop, the
"best_delta" variable is uninitialized so re-order the condition to
prevent reading uninitialized memory.

Fixes: 4aefe1c2 ("iio: imu: add Bosch Sensortec BNO055 core driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/Y0kuaO9PQkSQja+A@kiliSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/bno055/bno055.c

@@ -632,7 +632,7 @@ static int bno055_set_regmask(struct bno055_priv *priv, int val, int val2,
 			return -EINVAL;
 		}
 		delta = abs(tbl_val - req_val);
-		if (delta < best_delta || first) {
+		if (first || delta < best_delta) {
 			best_delta = delta;
 			hwval = i;
 			first = false;