net/atm/mpoa_proc.c: checkpatch cleanups

Convert #include <asm... to #include <linux...
Add printk argument verification to dprintk and ddprintk
Spacing cleanups
Mostly 80 column wrapped.
Removed unnecessary breaks after returns
Use %pI4 in seq_printf of IP address

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