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/logging/dynamic_logging.cc b/aos/logging/dynamic_logging.cc
index 1120a94..a3461b5 100644
--- a/aos/logging/dynamic_logging.cc
+++ b/aos/logging/dynamic_logging.cc
@@ -2,8 +2,7 @@
 
 #include "glog/logging.h"
 
-namespace aos {
-namespace logging {
+namespace aos::logging {
 
 DynamicLogging::DynamicLogging(aos::EventLoop *event_loop)
     : application_name_(event_loop->name()) {
@@ -31,5 +30,4 @@
   FLAGS_v = command.vlog_level();
 }
 
-}  // namespace logging
-}  // namespace aos
+}  // namespace aos::logging