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/realtime.cc b/aos/realtime.cc
index 22b864e..72daa6b 100644
--- a/aos/realtime.cc
+++ b/aos/realtime.cc
@@ -53,14 +53,13 @@
     FLAGS_tcmalloc_release_rate;
 
 namespace aos {
-namespace logging {
-namespace internal {
+
+namespace logging::internal {
 
 // Implemented in aos/logging/context.cc.
 void ReloadThreadName() __attribute__((weak));
 
-}  // namespace internal
-}  // namespace logging
+}  // namespace logging::internal
 
 namespace {