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/frc971/can_logger/can_logger.cc b/frc971/can_logger/can_logger.cc
index 7a6c0fe..e7e1e6f 100644
--- a/frc971/can_logger/can_logger.cc
+++ b/frc971/can_logger/can_logger.cc
@@ -1,7 +1,6 @@
 #include "frc971/can_logger/can_logger.h"
 
-namespace frc971 {
-namespace can_logger {
+namespace frc971::can_logger {
 
 CanLogger::CanLogger(aos::ShmEventLoop *event_loop,
                      std::string_view channel_name,
@@ -84,5 +83,4 @@
   return true;
 }
 
-}  // namespace can_logger
-}  // namespace frc971
+}  // namespace frc971::can_logger