message: remove unnecessary dynmaic cast
diff: @@ -114,11 +114,8 @@ void Bicg<ValueType, IndexType>::apply_impl(const LinOp *b, LinOp *x) const
  if (transposable_system_matrix) {
  trans_A = transposable_system_matrix->transpose();
  - } else {
  - auto csr_system_matrix_ =
  - dynamic_cast<const CsrMatrix *>(system_matrix_.get());
  - if (csr_system_matrix_ == nullptr) {
  + } else {
  csr_system_matrix_unique_ptr = copy_and_convert_to<CsrMatrix>(
  system_matrix_->get_executor(),
  const_cast<LinOp *>(system_matrix_.get()));
  @@ -126,8 +123,7 @@ void Bicg<ValueType, IndexType>::apply_impl(const LinOp *b, LinOp *x) const
  csr_system_matrix_unique_ptr->set_strategy(
  std::make_shared<typename CsrMatrix::classical>());
  - csr_system_matrix_ = csr_system_matrix_unique_ptr.get();
  - }
  + auto csr_system_matrix_ = csr_system_matrix_unique_ptr.get();
  trans_A = csr_system_matrix_->transpose();
  }
  