message: fix bicgstab
diff: @@ -108,7 +108,6 @@ void Bicgstab<ValueType>::apply_impl(const LinOp *b, LinOp *x) const
  system_matrix_, std::shared_ptr<const LinOp>(b, [](const LinOp *) {}),
  x, r.get());
  rr->copy_from(r.get());
  - system_matrix_->apply(r.get(), v.get());
  int iter = -1;
  while (true) {
  