ipath uses skb functions and won't build without CONFIG_NET.

Spotted by Randy Dunlap.
Signed-off-by: NBryan O'Sullivan <bryan.osullivan@qlogic.com>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>