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/util/log_interval.h b/aos/util/log_interval.h
index d346852..08d06bb 100644
--- a/aos/util/log_interval.h
+++ b/aos/util/log_interval.h
@@ -6,8 +6,7 @@
 #include "aos/logging/logging.h"
 #include "aos/time/time.h"
 
-namespace aos {
-namespace util {
+namespace aos::util {
 
 // A class to help with logging things that happen a lot only occasionally.
 //
@@ -91,7 +90,6 @@
   const char *context_ = NULL;
 };
 
-}  // namespace util
-}  // namespace aos
+}  // namespace aos::util
 
 #endif  // AOS_UTIL_LOG_INTERVAL_H_