rtnetlink: Add rtnexthop offload flag to compare mask

The offload flag is a status flag and should not be used by
FIB semantics for comparison.

Fixes: 37ed9493 ("rtnetlink: add RTNH_F_EXTERNAL flag for fib offload")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/rtnetlink.h

@@ -350,7 +350,7 @@ struct rtnexthop {
 #define RTNH_F_OFFLOAD		8	/* offloaded route */
 #define RTNH_F_LINKDOWN		16	/* carrier-down on nexthop */
 
-#define RTNH_COMPARE_MASK	(RTNH_F_DEAD | RTNH_F_LINKDOWN)
+#define RTNH_COMPARE_MASK	(RTNH_F_DEAD | RTNH_F_LINKDOWN | RTNH_F_OFFLOAD)
 
 /* Macros to handle hexthops */