mpi/tests/ring_kernel.cu: revert wrongly committed modification

mpi/tests/ring_kernel.cu

@@ -24,9 +24,9 @@ static __global__ void cuda_incrementer(int *token)
 
 extern "C" void increment_cuda(void *descr[], void *_args)
 {
-//	(void) _args;
-//	int *tokenptr = (int *)STARPU_VECTOR_GET_PTR(descr[0]);
-//
-//	cuda_incrementer<<<1,1, 0, starpu_cuda_get_local_stream()>>>(tokenptr);
-//	cudaStreamSynchronize(starpu_cuda_get_local_stream());
+	(void) _args;
+	int *tokenptr = (int *)STARPU_VECTOR_GET_PTR(descr[0]);
+
+	cuda_incrementer<<<1,1, 0, starpu_cuda_get_local_stream()>>>(tokenptr);
+	cudaStreamSynchronize(starpu_cuda_get_local_stream());
 }