ipv6: clean up rt6_clean_expires

Functionally, this change is a NOP.

Semantically, rt6_clean_expires() wants to do rt->dst.from = NULL instead of
rt->dst.expires = 0. It is clearing the RTF_EXPIRES flag, so the union is going
to be treated as a pointer (dst.from) not a long (dst.expires).
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip6_fib.h

@@ -129,7 +129,7 @@ static inline void rt6_clean_expires(struct rt6_info *rt)
 		dst_release(rt->dst.from);
 
 	rt->rt6i_flags &= ~RTF_EXPIRES;
-	rt->dst.expires = 0;
+	rt->dst.from = NULL;
 }
 
 static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires)