hwmon: (adt7462) ADT7462_REG_VOLT_MAX() should return 0

The callers never check for negative but they sometimes check for zero
returns:

	int reg = ADT7462_REG_VOLT_MAX(data, i);
        data->volt_max[i] =
		(reg ? i2c_smbus_read_byte_data(client, reg) : 0);

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
diff --git a/drivers/hwmon/adt7462.c b/drivers/hwmon/adt7462.c
index 69481d3..3e6aba1 100644
--- a/drivers/hwmon/adt7462.c
+++ b/drivers/hwmon/adt7462.c
@@ -333,7 +333,7 @@
 			return 0x4C;
 		break;
 	}
-	return -ENODEV;
+	return 0;
 }
 
 static int ADT7462_REG_VOLT_MIN(struct adt7462_data *data, int which)
@@ -392,7 +392,7 @@
 			return 0x77;
 		break;
 	}
-	return -ENODEV;
+	return 0;
 }
 
 static int ADT7462_REG_VOLT(struct adt7462_data *data, int which)