usbnet: Use wwan%d interface name for mobile broadband devices

Add support for usbnet based devices like CDC-Ether to indicate that they
are actually mobile broadband devices. In that case use wwan%d as default
interface name.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index ca5ca5a..8124cf1 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1295,6 +1295,9 @@
 		/* WLAN devices should always be named "wlan%d" */
 		if ((dev->driver_info->flags & FLAG_WLAN) != 0)
 			strcpy(net->name, "wlan%d");
+		/* WWAN devices should always be named "wwan%d" */
+		if ((dev->driver_info->flags & FLAG_WWAN) != 0)
+			strcpy(net->name, "wwan%d");
 
 		/* maybe the remote can't receive an Ethernet MTU */
 		if (net->mtu > (dev->hard_mtu - net->hard_header_len))