thermal: rockchip: fix a impossible condition caused by the warning

As the Dan report the smatch check the thermal driver warning:
drivers/thermal/rockchip_thermal.c:551 rockchip_configure_from_dt()
warn: impossible condition '(thermal->tshut_temp > ((~0 >> 1))) =>
(s32min-s32max > s32max)'

Although The shut_temp read from DT is u32,the temperature is currently
represented as int not long in the thermal driver.
Let's change to make shut_temp instead of the thermal->tshut_temp for
the condition.

Fixes: commit 437df217
("thermal: rockchip: consistently use int for temperatures")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

drivers/thermal/rockchip_thermal.c

@@ -693,14 +693,13 @@ static int rockchip_configure_from_dt(struct device *dev,
 			 thermal->chip->tshut_temp);
 		thermal->tshut_temp = thermal->chip->tshut_temp;
 	} else {
-		thermal->tshut_temp = shut_temp;
-	}
-
-	if (thermal->tshut_temp > INT_MAX) {
+		if (shut_temp > INT_MAX) {
 			dev_err(dev, "Invalid tshut temperature specified: %d\n",
-			thermal->tshut_temp);
+				shut_temp);
 			return -ERANGE;
 		}
+		thermal->tshut_temp = shut_temp;
+	}
 
 	if (of_property_read_u32(np, "rockchip,hw-tshut-mode", &tshut_mode)) {
 		dev_warn(dev,