This patch fixes the following checkpatch warning:

WARNING: Prefer netdev_dbg(netdev, ... then dev_dbg(dev, ... then
pr_debug(...  to printk(KERN_DEBUG ...
Signed-off-by: Teodora Baluta <teobaluta@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>