hwmon: (nct7904) Fix incorrect range of temperature limit registers

The format of temperature limitation registers are 8-bit 2's complement
and the range is -128~127.
Converts the reading value to signed char to fix the incorrect range
of temperature limitation registers.
Signed-off-by: Amy Shih <amy.shih@advantech.com.tw>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/nct7904.c

@@ -362,6 +362,7 @@ static int nct7904_read_temp(struct device *dev, u32 attr, int channel,
 	struct nct7904_data *data = dev_get_drvdata(dev);
 	int ret, temp;
 	unsigned int reg1, reg2, reg3;
+	s8 temps;
 
 	switch (attr) {
 	case hwmon_temp_input:
@@ -467,7 +468,8 @@ static int nct7904_read_temp(struct device *dev, u32 attr, int channel,
 
 	if (ret < 0)
 		return ret;
-	*val = ret * 1000;
+	temps = ret;
+	*val = temps * 1000;
 	return 0;
 }