Fix compilation error when _CLK_BREAKDOWN is defined in cagra.

PR #1740 forgot to rename `BLOCK_SIZE` in `#ifdef _CLK_BREAKDOWN`
blocks.

also remove an unused function in search_single_cta_kernel-inl.cuh

cpp/include/raft/neighbors/detail/cagra/search_multi_cta_kernel-inl.cuh

@@ -209,7 +209,7 @@ __launch_bounds__(1024, 1) RAFT_KERNEL search_kernel(
 
 #if 0
     /* debug */
-    for (unsigned i = threadIdx.x; i < result_buffer_size_32; i += BLOCK_SIZE) {
+    for (unsigned i = threadIdx.x; i < result_buffer_size_32; i += blockDim.x) {
         result_indices_buffer[i] = utils::get_max_value<INDEX_T>();
         result_distances_buffer[i] = utils::get_max_value<DISTANCE_T>();
     }
@@ -351,7 +351,7 @@ __launch_bounds__(1024, 1) RAFT_KERNEL search_kernel(
   }
 
 #ifdef _CLK_BREAKDOWN
-  if ((threadIdx.x == 0 || threadIdx.x == BLOCK_SIZE - 1) && (blockIdx.x == 0) &&
+  if ((threadIdx.x == 0 || threadIdx.x == blockDim.x - 1) && (blockIdx.x == 0) &&
       ((query_id * 3) % gridDim.y < 3)) {
     RAFT_LOG_DEBUG(
       "query, %d, thread, %d"

cpp/include/raft/neighbors/detail/cagra/search_single_cta_kernel-inl.cuh

@@ -448,14 +448,6 @@ __device__ inline void hashmap_restore(INDEX_T* const hashmap_ptr,
   }
 }
 
-template <class T, unsigned BLOCK_SIZE>
-__device__ inline void set_value_device(T* const ptr, const T fill, const std::uint32_t count)
-{
-  for (std::uint32_t i = threadIdx.x; i < count; i += BLOCK_SIZE) {
-    ptr[i] = fill;
-  }
-}
-
 // One query one thread block
 template <uint32_t TEAM_SIZE,
           uint32_t DATASET_BLOCK_DIM,
@@ -791,7 +783,7 @@ __launch_bounds__(1024, 1) RAFT_KERNEL search_kernel(
     num_executed_iterations[query_id] = iter + 1;
   }
 #ifdef _CLK_BREAKDOWN
-  if ((threadIdx.x == 0 || threadIdx.x == BLOCK_SIZE - 1) && ((query_id * 3) % gridDim.y < 3)) {
+  if ((threadIdx.x == 0 || threadIdx.x == blockDim.x - 1) && ((query_id * 3) % gridDim.y < 3)) {
     RAFT_LOG_DEBUG(
       "query, %d, thread, %d"
       ", init, %d"