[PATCH] IPoIB: set skb->mac.raw on receive

Set skb->mac.raw on receive.  This fixes crashes when this is
dereferenced, for example by netfilter or when PF_PACKET is used.

Signed-off-by: Hal Rosenstock <halr@voltaire.com>
Signed-off-by: Roland Dreier <roland@topspin.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>