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/include/net/dn_route.h b/include/net/dn_route.h
index 60c9f22..ccadab3 100644
--- a/include/net/dn_route.h
+++ b/include/net/dn_route.h
@@ -65,9 +65,7 @@
  * packets to the originating host.
  */
 struct dn_route {
-	union {
-		struct dst_entry dst;
-	} u;
+	struct dst_entry dst;
 
 	struct flowi fl;