ipv4: Allocate fib metrics dynamically.

This is the initial gateway towards super-sharing metrics
if they are all set to zero for a route.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 65d1fcd..2c0508a 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -77,7 +77,7 @@
 	int			fib_protocol;
 	__be32			fib_prefsrc;
 	u32			fib_priority;
-	u32			fib_metrics[RTAX_MAX];
+	u32			*fib_metrics;
 #define fib_mtu fib_metrics[RTAX_MTU-1]
 #define fib_window fib_metrics[RTAX_WINDOW-1]
 #define fib_rtt fib_metrics[RTAX_RTT-1]