Nest some more namespaces

Did someone previously suggest that all namespace had been
nested?  Silly.

Signed-off-by: Stephan Pleines <pleines.stephan@gmail.com>
Change-Id: I22278c1caaeba8b47dc46fb2ed3078c20a11e190
diff --git a/aos/vision/events/tcp_server.h b/aos/vision/events/tcp_server.h
index 24b4f60..49a5a8c 100644
--- a/aos/vision/events/tcp_server.h
+++ b/aos/vision/events/tcp_server.h
@@ -7,8 +7,7 @@
 #include "aos/vision/events/epoll_events.h"
 #include "aos/vision/events/intrusive_free_list.h"
 
-namespace aos {
-namespace events {
+namespace aos::events {
 
 // Non-templatized base class of TCP server.
 // TCPServer implements Construct which specializes the client connection
@@ -71,7 +70,6 @@
   }
 };
 
-}  // namespace events
-}  // namespace aos
+}  // namespace aos::events
 
 #endif  // _AOS_VISION_EVENTS_TCP_SERVER_H_