hwmon: (nct6683) Add missing sysfs attribute initialization

The following error message is seen when loading the nct6683 driver
with DEBUG_LOCK_ALLOC enabled.

BUG: key ffff88040b2f0030 not in .data!
------------[ cut here ]------------
WARNING: CPU: 0 PID: 186 at kernel/locking/lockdep.c:2988
				lockdep_init_map+0x469/0x630()
DEBUG_LOCKS_WARN_ON(1)

Caused by a missing call to sysfs_attr_init() when initializing
sysfs attributes.
Reported-by: NAlexey Orishko <alexey.orishko@gmail.com>
Reviewed-by: NJean Delvare <jdelvare@suse.de>
Cc: stable@vger.kernel.org # v3.18+
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

drivers/hwmon/nct6683.c

@@ -439,6 +439,7 @@ nct6683_create_attr_group(struct device *dev, struct sensor_template_group *tg,
 				 (*t)->dev_attr.attr.name, tg->base + i);
 			if ((*t)->s2) {
 				a2 = &su->u.a2;
+				sysfs_attr_init(&a2->dev_attr.attr);
 				a2->dev_attr.attr.name = su->name;
 				a2->nr = (*t)->u.s.nr + i;
 				a2->index = (*t)->u.s.index;
@@ -449,6 +450,7 @@ nct6683_create_attr_group(struct device *dev, struct sensor_template_group *tg,
 				*attrs = &a2->dev_attr.attr;
 			} else {
 				a = &su->u.a1;
+				sysfs_attr_init(&a->dev_attr.attr);
 				a->dev_attr.attr.name = su->name;
 				a->index = (*t)->u.index + i;
 				a->dev_attr.attr.mode =