Allow IP over IB to work with multiple FIBs.

Call M_SETFIB() to make sure the IPoIB packet is directed to the correct
interface-specific FIB.

This was sufficient to allow general-purpose routing using the default FIB,
and a separate FIB for routing between IPoIB on ib0 and IPoEthernet on mce0.

Reviewed by:	hselasky
Obtained from:	Anmol Kumar <anmolk at panasas dot com>
MFC after:	1 week
Sponsored by:	Panasas
Differential Revision:	https://reviews.freebsd.org/D25239

sys/ofed/drivers/infiniband/ulp/ipoib/ipoib_main.c

@@ -1617,6 +1617,8 @@ ipoib_demux(struct ifnet *ifp, struct mbuf *m, u_short proto)
 		m_freem(m);
 		return;
 	}
+	/* Direct packet to correct FIB based on interface config */
+	M_SETFIB(m, ifp->if_fib);
 	/*
 	 * Dispatch frame to upper layer.
 	 */