Make dev->authorized private to audio/device.c

There's no need to expose the authorized setting outside of device.c.
diff --git a/audio/device.c b/audio/device.c
index f2ddd24..d60e359 100644
--- a/audio/device.c
+++ b/audio/device.c
@@ -91,6 +91,8 @@
 	guint control_timer;
 	guint avdtp_timer;
 	guint headset_timer;
+
+	gboolean authorized;
 };
 
 static unsigned int sink_callback_id = 0;
@@ -151,7 +153,7 @@
 		return;
 
 	if (new_state == AUDIO_STATE_DISCONNECTED)
-		dev->authorized = FALSE;
+		priv->authorized = FALSE;
 
 	if (dev->priv->state == new_state) {
 		debug("state change attempted from %s to %s",
@@ -683,7 +685,7 @@
 	struct dev_priv *priv = dev->priv;
 
 	if (derr == NULL)
-		dev->authorized = TRUE;
+		priv->authorized = TRUE;
 
 	while (priv->auths) {
 		struct service_auth *auth = priv->auths->data;
@@ -749,7 +751,7 @@
 	if (g_slist_length(priv->auths) > 1)
 		return 0;
 
-	if (dev->authorized || audio_device_is_connected(dev)) {
+	if (priv->authorized || audio_device_is_connected(dev)) {
 		g_idle_add(auth_idle_cb, dev);
 		return 0;
 	}
diff --git a/audio/device.h b/audio/device.h
index f4d8390..45c54e8 100644
--- a/audio/device.h
+++ b/audio/device.h
@@ -59,7 +59,6 @@
 	bdaddr_t dst;
 
 	gboolean auto_connect;
-	gboolean authorized;
 
 	struct headset *headset;
 	struct gateway *gateway;