Bluetooth: Convert to use ATTRIBUTE_GROUPS macro

Use ATTRIBUTE_GROUPS macro to reduce the number of lines of code.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

net/bluetooth/hci_sysfs.c

@@ -49,14 +49,7 @@ static struct attribute *bt_link_attrs[] = {
 	NULL
 };
 
-static struct attribute_group bt_link_group = {
-	.attrs = bt_link_attrs,
-};
-
-static const struct attribute_group *bt_link_groups[] = {
-	&bt_link_group,
-	NULL
-};
+ATTRIBUTE_GROUPS(bt_link);
 
 static void bt_link_release(struct device *dev)
 {
@@ -182,14 +175,7 @@ static struct attribute *bt_host_attrs[] = {
 	NULL
 };
 
-static struct attribute_group bt_host_group = {
-	.attrs = bt_host_attrs,
-};
-
-static const struct attribute_group *bt_host_groups[] = {
-	&bt_host_group,
-	NULL
-};
+ATTRIBUTE_GROUPS(bt_host);
 
 static void bt_host_release(struct device *dev)
 {