Nest all namespaces

The compiler supports this now.  We can type less going forward.
No functional changes.

Signed-off-by: Stephan Pleines <pleines.stephan@gmail.com>
Change-Id: I29d6fa4f9aacc0e381f1a7637294db0392466995
diff --git a/aos/events/logging/log_writer.cc b/aos/events/logging/log_writer.cc
index bc81a4b..f840c22 100644
--- a/aos/events/logging/log_writer.cc
+++ b/aos/events/logging/log_writer.cc
@@ -13,8 +13,7 @@
 #include "aos/network/timestamp_channel.h"
 #include "aos/sha256.h"
 
-namespace aos {
-namespace logger {
+namespace aos::logger {
 namespace {
 using message_bridge::RemoteMessage;
 namespace chrono = std::chrono;
@@ -921,5 +920,4 @@
   }
 }
 
-}  // namespace logger
-}  // namespace aos
+}  // namespace aos::logger