hwmon: (lm90) Prevent integer underflows of temperature calculations

The min/max/crit and all other temperature values that are passed to
the driver are unlimited and value that is close to INT_MIN results in
integer underflow of the temperature calculations made by the driver
for LM99 sensor. Temperature hysteresis is among those values that need
to be limited, but limiting of hysteresis is independent from the sensor
version. Add the missing limits.

Signed-off-by: Dmitry Osipenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Guenter Roeck <[e-mail]>

drivers/hwmon/lm90.c

···
 	int err;
 
 	/* +16 degrees offset for temp2 for the LM99 */
-	if (data->kind == lm99 && index <= 2)
+	if (data->kind == lm99 && index <= 2) {
+		/* prevent integer underflow */
+		val = max(val, -128000l);
 		val -= 16000;
+	}
 
 	if (data->kind == adt7461 || data->kind == tmp451)
 		data->temp11[index] = temp_to_u16_adt7461(data, val);
···
 	int err;
 
 	/* +16 degrees offset for temp2 for the LM99 */
-	if (data->kind == lm99 && index == 3)
+	if (data->kind == lm99 && index == 3) {
+		/* prevent integer underflow */
+		val = max(val, -128000l);
 		val -= 16000;
+	}
 
 	if (data->kind == adt7461 || data->kind == tmp451)
 		data->temp8[index] = temp_to_u8_adt7461(data, val);
···
 		temp = temp_from_u8(data->temp8[LOCAL_CRIT]);
 	else
 		temp = temp_from_s8(data->temp8[LOCAL_CRIT]);
+
+	/* prevent integer underflow */
+	val = max(val, -128000l);
 
 	data->temp_hyst = hyst_to_reg(temp - val);
 	err = i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,