ipv6: Simplify rt6_qualify_for_ecmp

After commit c7a1ce39 ("ipv6: Change addrconf_f6i_alloc to use
ip6_route_info_create"), the gateway is no longer filled in for fib6_nh
structs in a prefix route. Accordingly, the RTF_ADDRCONF flag check can
be dropped from the 'rt6_qualify_for_ecmp'.

Further, RTF_DYNAMIC is only set in rt6_info instances, so it can be
removed from the check as well.

This reduces rt6_qualify_for_ecmp and the mlxsw version to just checking
if the nexthop has a gateway which is the real indication of whether
entries can be coalesced into a multipath route.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -4928,7 +4928,7 @@ static void mlxsw_sp_rt6_destroy(struct mlxsw_sp_rt6 *mlxsw_sp_rt6)
 static bool mlxsw_sp_fib6_rt_can_mp(const struct fib6_info *rt)
 {
 	/* RTF_CACHE routes are ignored */
-	return !(rt->fib6_flags & RTF_ADDRCONF) && rt->fib6_nh.fib_nh_gw_family;
+	return rt->fib6_nh.fib_nh_gw_family;
 }
 
 static struct fib6_info *

include/net/ip6_route.h

@@ -68,8 +68,7 @@ static inline bool rt6_need_strict(const struct in6_addr *daddr)
 
 static inline bool rt6_qualify_for_ecmp(const struct fib6_info *f6i)
 {
-	return !(f6i->fib6_flags & (RTF_ADDRCONF|RTF_DYNAMIC)) &&
-		f6i->fib6_nh.fib_nh_gw_family;
+	return f6i->fib6_nh.fib_nh_gw_family;
 }
 
 void ip6_route_input(struct sk_buff *skb);