drivers/net/mac8390.c: Convert printk(KERN_<level> to pr_<level>(

Use printk_once
Add #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
Convert printks without KERN_<level> to pr_info and pr_cont

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