[Bluetooth] Always include MTU in L2CAP config responses

When sending a positive config response it shall include the actual
MTU to be used on this channel. This differs from the Bluetooth 1.1
specification where it was enough to acknowledge the config request.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 2b3dcb8..c09d4a2 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1353,12 +1353,12 @@
 
 	/* Configure output options and let the other side know
 	 * which ones we don't like. */
-	if (pi->conf_mtu < pi->omtu) {
-		l2cap_add_conf_opt(ptr, L2CAP_CONF_MTU, 2, pi->omtu);
+	if (pi->conf_mtu < pi->omtu)
 		result = L2CAP_CONF_UNACCEPT;
-	} else {
+	else
 		pi->omtu = pi->conf_mtu;
-	}
+
+	l2cap_add_conf_opt(ptr, L2CAP_CONF_MTU, 2, pi->omtu);
 
 	BT_DBG("sk %p result %d", sk, result);
 	return result;