Staging: otus: fix assignment makes integer from pointer without a cast warnings

This patch fixes some %x pointer printing to %p.

It also uses the skb_tail_pointer and skb_mac_header macros for accessing
thos members.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>