Bluetooth: Fix format arguments warning

Newer GCC versions are a little bit picky about how to deal with format
arguments:

net/bluetooth/hci_sysfs.c: In function ‘hci_register_sysfs’:
net/bluetooth/hci_sysfs.c:418: warning: format not a string literal and no format arguments

It is simple enough to fix and makes the compiler happy.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/hci_sysfs.c b/net/bluetooth/hci_sysfs.c
index 6490bf8..1a1f916 100644
--- a/net/bluetooth/hci_sysfs.c
+++ b/net/bluetooth/hci_sysfs.c
@@ -415,7 +415,7 @@
 	dev->class = bt_class;
 	dev->parent = hdev->parent;
 
-	dev_set_name(dev, hdev->name);
+	dev_set_name(dev, "%s", hdev->name);
 
 	dev_set_drvdata(dev, hdev);