Update atomic example to be more stable

Author: ZzEeKkAa

numba_dpex/examples/kernel/atomic_op.py

@@ -10,12 +10,14 @@
 @ndpx.kernel
 def atomic_reduction(a):
     idx = ndpx.get_global_id(0)
-    ndpx.atomic.add(a, 0, a[idx])
+    ndpx.atomic.add(a, 0, a[idx + 1])
 
 
 def main():
     N = 10
-    a = np.arange(N)
+
+    # We are storing sum to the first element
+    a = np.arange(0, N + 1)
 
     print("Using device ...")
     print(a.device)