remove global count sort

src/radix_sort_parallel.cu

@@ -99,7 +99,7 @@ void count_sort(int* d_arr, int n, int idx) {
 
 void radix_sort(int* d_arr, int n) { 
     for (int idx = 1; idx < 32; idx++) {
-        count_sort<<<grid_dim, block_dim>>>(d_arr, n, idx);
+        count_sort(d_arr, n, idx);
     }
 }