[NET]: dst_ifdown() cleanup

This cleanup shrinks size of net/core/dst.o on i386 from 1299 to 1289 bytes.
(This is because dev_hold()/dev_put() are doing atomic_inc()/atomic_dec() and
force compiler to re-evaluate memory contents.)
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/dst.c

@@ -284,8 +284,8 @@ static inline void dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 		dev_put(dev);
 		if (dst->neighbour && dst->neighbour->dev == dev) {
 			dst->neighbour->dev = dst->dev;
+			dev_hold(dst->dev);
 			dev_put(dev);
-			dev_hold(dst->neighbour->dev);
 		}
 	}
 }