ipv4: Maintain redirect and PMTU info in struct rtable again.

Maintaining this in the inetpeer entries was not the right way to do
this at all.

Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/route.h

@@ -65,7 +65,7 @@ struct rtable {
 	__be32			rt_gateway;
 
 	/* Miscellaneous cached information */
-	u32			rt_peer_genid;
+	u32			rt_pmtu;
 	unsigned long		_peer; /* long-living peer info */
 	struct fib_info		*fi; /* for client ref to shared metrics */
 };