mlxsw: spectrum_router: Add missing rollback

With this patch the error path of mlxsw_sp_nexthop_init() is symmetric
with mlxsw_sp_nexthop_fini(). Noticed during code review.

Fixes: a8c97014 ("mlxsw: spectrum_router: Refactor nexthop init routine")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

@@ -1790,6 +1790,7 @@ static int mlxsw_sp_nexthop_init(struct mlxsw_sp *mlxsw_sp,
 	return 0;
 
 err_nexthop_neigh_init:
+	mlxsw_sp_nexthop_rif_fini(nh);
 	mlxsw_sp_nexthop_remove(mlxsw_sp, nh);
 	return err;
 }