Shorten expression.

src/xt_request_msgs.c

@@ -92,7 +92,7 @@ Xt_request xt_request_msgs_new(int n, MPI_Request * requests,
   request->n = n;
   request->comm = comm;
   request->ops_completed_buffer =
-    (int*)((char*)request + sizeof(*request) + (size_t)n * sizeof(MPI_Request));
+    (int *)(request->requests + (size_t)n);
   memcpy(request->requests, requests, (size_t)n * sizeof(*request->requests));
 
   return (Xt_request)request;