hwmon: (adt7475) Make adt7475_read_word() return errors

BugLink: https://bugs.launchpad.net/bugs/1798770

[ Upstream commit f196dec6 ]

The adt7475_read_word() function was meant to return negative error
codes on failure.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Tokunori Ikegami <ikegami@allied-telesis.co.jp>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/hwmon/adt7475.c

@@ -274,14 +274,18 @@ static inline u16 volt2reg(int channel, long volt, u8 bypass_attn)
 	return clamp_val(reg, 0, 1023) & (0xff << 2);
 }
 
-static u16 adt7475_read_word(struct i2c_client *client, int reg)
+static int adt7475_read_word(struct i2c_client *client, int reg)
 {
-	u16 val;
+	int val1, val2;
 
-	val = i2c_smbus_read_byte_data(client, reg);
-	val |= (i2c_smbus_read_byte_data(client, reg + 1) << 8);
+	val1 = i2c_smbus_read_byte_data(client, reg);
+	if (val1 < 0)
+		return val1;
+	val2 = i2c_smbus_read_byte_data(client, reg + 1);
+	if (val2 < 0)
+		return val2;
 
-	return val;
+	return val1 | (val2 << 8);
 }
 
 static void adt7475_write_word(struct i2c_client *client, int reg, u16 val)