CDC-NCM: remove "connected" log message

The cdc_ncm driver passes network connection notifications up to
usbnet_link_change(), which is the right place for any logging.
Remove the netdev_info() duplicating this from the driver itself.

This stops devices such as my "TRENDnet USB 10/100/1G/2.5G LAN"
(ID 20f4:e02b) adapter from spamming the kernel log with

    cdc_ncm 2-2:2.0 enp0s2u2c2: network connection: connected

messages every 60 msec or so.
Signed-off-by: Roland Dreier <roland@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20201224032116.2453938-1-roland@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/usb/cdc_ncm.c

@@ -1863,9 +1863,6 @@ static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
 		 * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
 		 * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
 		 */
-		netif_info(dev, link, dev->net,
-			   "network connection: %sconnected\n",
-			   !!event->wValue ? "" : "dis");
 		usbnet_link_change(dev, !!event->wValue, 0);
 		break;