message: fix opposite is_supported checks
diff: @@ -314,8 +314,9 @@ void spmv(std::shared_ptr<const CudaExecutor> exec,
  #if defined(CUDA_VERSION) && (CUDA_VERSION < 11000)
  // TODO: add implementation for int64 and multiple RHS
  - if (cusparse::is_supported<ValueType, IndexType>::value)
  + if (!cusparse::is_supported<ValueType, IndexType>::value) {
  GKO_NOT_IMPLEMENTED;
  + }
  auto descr = cusparse::create_mat_descr();
  auto row_ptrs = a->get_const_row_ptrs();
  @@ -399,8 +400,9 @@ void advanced_spmv(std::shared_ptr<const CudaExecutor> exec,
  if (b->get_stride() != 1 || c->get_stride() != 1) GKO_NOT_IMPLEMENTED;
  #if defined(CUDA_VERSION) && (CUDA_VERSION < 11000)
  - if (cusparse::is_supported<ValueType, IndexType>::value)
  + if (!cusparse::is_supported<ValueType, IndexType>::value) {
  GKO_NOT_IMPLEMENTED;
  + }
  auto descr = cusparse::create_mat_descr();
  auto row_ptrs = a->get_const_row_ptrs();
  @@ -509,8 +511,9 @@ void spgemm(std::shared_ptr<const CudaExecutor> exec,
  auto& c_vals_array = c_builder.get_value_array();
  #if defined(CUDA_VERSION) && (CUDA_VERSION < 11000)
  - if (cusparse::is_supported<ValueType, IndexType>::value)
  + if (!cusparse::is_supported<ValueType, IndexType>::value) {
  GKO_NOT_IMPLEMENTED;
  + }
  auto a_descr = cusparse::create_mat_descr();
  auto b_descr = cusparse::create_mat_descr();
  @@ -675,8 +678,9 @@ void advanced_spgemm(std::shared_ptr<const CudaExecutor> exec,
  auto c_row_ptrs = c->get_row_ptrs();
  #if defined(CUDA_VERSION) && (CUDA_VERSION < 11000)
  - if (cusparse::is_supported<ValueType, IndexType>::value)
  + if (!cusparse::is_supported<ValueType, IndexType>::value) {
  GKO_NOT_IMPLEMENTED;
  + }
  matrix::CsrBuilder<ValueType, IndexType> c_builder{c};
  auto& c_col_idxs_array = c_builder.get_col_idx_array();
  