CDC-NCM: remove "connected" log message

CDC-NCM: remove "connected" log message

BugLink: https://bugs.launchpad.net/bugs/1913486
[ Upstream commit 59b4a8fa27f5a895582ada1ae5034af7c94a57b5 ]

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.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: William Breathitt Gray <william.gray@canonical.com>