ethernet: Convert dev_printk(KERN_<LEVEL> to dev_<level>(

dev_<level> calls take less code than dev_printk(KERN_<LEVEL>
and reducing object size is good.
Coalesce formats for easier grep.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>