mlxsw: spectrum_router: Split nexthop finalization to two stages

Nexthop finalization consists of two steps: the part where the offload is
removed, because the backing RIF is now gone; and the part where the
association to the RIF is severed.

Extract from mlxsw_sp_nexthop_type_fini() a helper that covers the
unoffloading part, mlxsw_sp_nexthop_type_rif_gone(), so that it can later
be called independently.

Note that this swaps around the ordering of mlxsw_sp_nexthop_ipip_fini()
vs. mlxsw_sp_nexthop_rif_fini(). The current ordering is more of a
historical happenstance than a conscious decision. The two cleanups do not
depend on each other, and this change should have no observable effects.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Danielle Ratson <danieller@nvidia.com>
Link: https://lore.kernel.org/r/7134559534c5f5c4807c3a1569fae56f8887e763.1687438411.git.petrm@nvidia.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

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

@@ -4369,21 +4369,26 @@ static int mlxsw_sp_nexthop_type_init(struct mlxsw_sp *mlxsw_sp,
 	return err;
 }
 
-static void mlxsw_sp_nexthop_type_fini(struct mlxsw_sp *mlxsw_sp,
-				       struct mlxsw_sp_nexthop *nh)
+static void mlxsw_sp_nexthop_type_rif_gone(struct mlxsw_sp *mlxsw_sp,
+					   struct mlxsw_sp_nexthop *nh)
 {
 	switch (nh->type) {
 	case MLXSW_SP_NEXTHOP_TYPE_ETH:
 		mlxsw_sp_nexthop_neigh_fini(mlxsw_sp, nh);
-		mlxsw_sp_nexthop_rif_fini(nh);
 		break;
 	case MLXSW_SP_NEXTHOP_TYPE_IPIP:
-		mlxsw_sp_nexthop_rif_fini(nh);
 		mlxsw_sp_nexthop_ipip_fini(mlxsw_sp, nh);
 		break;
 	}
 }
 
+static void mlxsw_sp_nexthop_type_fini(struct mlxsw_sp *mlxsw_sp,
+				       struct mlxsw_sp_nexthop *nh)
+{
+	mlxsw_sp_nexthop_type_rif_gone(mlxsw_sp, nh);
+	mlxsw_sp_nexthop_rif_fini(nh);
+}
+
 static int mlxsw_sp_nexthop4_init(struct mlxsw_sp *mlxsw_sp,
 				  struct mlxsw_sp_nexthop_group *nh_grp,
 				  struct mlxsw_sp_nexthop *nh,