Update prints to have which node they are from

This is enormously helpful when trying to debug the sorting flow.

Change-Id: Ia95acd3204d0ce241455805fc63f7886e88f014b
diff --git a/aos/events/logging/log_cat.cc b/aos/events/logging/log_cat.cc
index b31bba0..38bd390 100644
--- a/aos/events/logging/log_cat.cc
+++ b/aos/events/logging/log_cat.cc
@@ -212,8 +212,9 @@
     printer_event_loops.emplace_back(std::move(printer_event_loop));
 
     std::cout << std::endl;
-    std::cout << "Log starting at " << reader.realtime_start_time() << " ("
-              << reader.monotonic_start_time() << ")";
+    std::cout << (node != nullptr ? (node->name()->str() + " ") : "")
+              << "Log starting at " << reader.realtime_start_time(node) << " ("
+              << reader.monotonic_start_time(node) << ")";
     std::cout << std::endl << std::endl;
   }