build error in v3.18.y.stable-queue

[Guenter Roeck <linux@xxxxxxxxxxxx>]

net/ipv4/fib_frontend.c: In function ‘fib_compute_spec_dst’:
net/ipv4/fib_frontend.c:225:3: error: expected expression before ‘if’
   if (!fib_lookup(net, &fl4, &res))

Looking into the source, it is indeed bad.

                fl4.flowi4_mark = vmark ? skb->mark : 0,
		if (!fib_lookup(net, &fl4, &res))
			return FIB_RES_PREFSRC(net, res);

Guenter