Fixed redundant contexts in multi-process apps

Change-Id: If787014450fd281304f0c7baf01d25963e40905d

test/mpi/mpi_test.cu

@@ -70,7 +70,7 @@ int main(int argc, char *argv[]) {
 
   // CUDA stream creation
   cudaStream_t stream;
-  cudaStreamCreateWithFlags(&stream, cudaStreamNonBlocking);
+  CUDACHECK(cudaStreamCreateWithFlags(&stream, cudaStreamNonBlocking));
 
   // Initialize input values
   int *dptr;
@@ -91,7 +91,7 @@ int main(int argc, char *argv[]) {
   }
 
   // Check results
-  cudaStreamSynchronize(stream);
+  CUDACHECK(cudaStreamSynchronize(stream));
   CUDACHECK(cudaMemcpy(val, (dptr+SIZE), SIZE*sizeof(int), cudaMemcpyDeviceToHost));
   for (int v=0; v<SIZE; v++) {
     if (val[v] != ref) {