hwmon: (adt7470) fix checkpatch issues

fixed:
ERROR: that open brace { should be on the previous line
#1135: FILE: adt7470.c:1135:
+static struct attribute *adt7470_attr[] =
+{

ERROR: do not use assignment in if condition
#1279: FILE: adt7470.c:1279:
+	if ((err = sysfs_create_group(&client->dev.kobj, &data->attrs)))

Signed-off-by: Frans Meulenbroeks <fransmeulenbroeks@gmail.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>