mlxsw: spectrum_router: Re-order mlxsw_sp_nexthop6_group_get()

Attach the FIB entry to the nexthop group after setting the offload flag
on the IPv6 FIB info (i.e., 'struct fib6_info'). The second operation is
not needed when the nexthop group is a nexthop object. This will allow
us to have a common exit path from the function, regardless of the
nexthop group's type.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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

@@ -5508,15 +5508,15 @@ static int mlxsw_sp_nexthop6_group_get(struct mlxsw_sp *mlxsw_sp,
 			return PTR_ERR(nh_grp);
 	}
 
-	list_add_tail(&fib6_entry->common.nexthop_group_node,
-		      &nh_grp->fib_list);
-	fib6_entry->common.nh_group = nh_grp;
-
 	/* The route and the nexthop are described by the same struct, so we
 	 * need to the update the nexthop offload indication for the new route.
 	 */
 	__mlxsw_sp_nexthop6_group_offload_refresh(nh_grp, fib6_entry);
 
+	list_add_tail(&fib6_entry->common.nexthop_group_node,
+		      &nh_grp->fib_list);
+	fib6_entry->common.nh_group = nh_grp;
+
 	return 0;
 }