Fix gather index type in ann_ivf_flat test

Author: huuanhhuyn

cpp/tests/neighbors/ann_ivf_flat.cuh

@@ -311,10 +311,10 @@ class AnnIVFFlatTest : public ::testing::TestWithParam<AnnIvfFlatInputs<IdxT>> {
 
         raft::matrix::gather(
           handle_,
-          raft::make_device_matrix_view<const DataT, uint32_t>(
-            (const DataT*)database.data(), static_cast<uint32_t>(ps.num_db_vecs), idx.dim()),
-          raft::make_device_vector_view<const IdxT, uint32_t>((const IdxT*)list_inds.data_handle(),
-                                                              list_size),
+          raft::make_device_matrix_view<const DataT, int32_t>(
+            (const DataT*)database.data(), static_cast<int32_t>(ps.num_db_vecs), idx.dim()),
+          raft::make_device_vector_view<const IdxT, int32_t>((const IdxT*)list_inds.data_handle(),
+                                                             list_size),
           flat_codes.view());
 
         helpers::codepacker::pack(