net-next: remove useless union keyword

remove useless union keyword in rtable, rt6_info and dn_route.

Since there is only one member in a union, the union keyword isn't useful.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index eedf2c9..b898364 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -127,7 +127,7 @@
 
 #ifdef CONFIG_BRIDGE_NETFILTER
 	/* remember the MTU in the rtable for PMTU */
-	br->fake_rtable.u.dst.metrics[RTAX_MTU - 1] = new_mtu;
+	br->fake_rtable.dst.metrics[RTAX_MTU - 1] = new_mtu;
 #endif
 
 	return 0;