bluetooth: host: fix compile break with CONFIG_ASSERT in gatt.c

Fix the attr->handler reference to attr->handle.

Change-Id: I4a6ccee7860abf800f51df404979eac18eb26e8e
Signed-off-by: Michael Scott <[email protected]>

Author: Michael Scott

subsys/bluetooth/host/gatt.c

@@ -560,7 +560,7 @@ int bt_gatt_notify(struct bt_conn *conn, const struct bt_gatt_attr *attr,
 {
 	struct notify_data nfy;
 
-	__ASSERT(attr && attr->handler, "invalid parameters\n");
+	__ASSERT(attr && attr->handle, "invalid parameters\n");
 
 	if (conn) {
 		return gatt_notify(conn, attr->handle, data, len);