net: cdc_ncm: use netif_* and dev_* instead of pr_*

Take advantage of standard device name prefixing and
netdevice msglvl control where possible.

Cc: Alexey Orishko <alexey.orishko@gmail.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>