message: update cuda kernel definition for blocksize template
diff: @@ -122,7 +122,7 @@ void REDUCE_STRUCT::runCudaVariantImpl(VariantID vid)
  cudaErrchk(cudaMemsetAsync(mem, 0.0, 6*sizeof(Real_type)));
  const size_t grid_size = RAJA_DIVIDE_CEILING_INT(iend, block_size);
  - reduce_struct<<<grid_size, block_size,6*sizeof(Real_type)*block_size>>>
  + reduce_struct<block_size><<<grid_size, block_size,6*sizeof(Real_type)*block_size>>>
  (particles.x, particles.y,
  mem, mem+1,mem+2, //xcenter,xmin,xmax
  mem+3,mem+4,mem+5, //ycenter,ymin,ymax
  