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/frc971/wpilib/buffered_pcm.h b/frc971/wpilib/buffered_pcm.h
index f743371..4933c25 100644
--- a/frc971/wpilib/buffered_pcm.h
+++ b/frc971/wpilib/buffered_pcm.h
@@ -7,8 +7,7 @@
 
 #include "frc971/wpilib/buffered_solenoid.h"
 
-namespace frc971 {
-namespace wpilib {
+namespace frc971::wpilib {
 
 // Manages setting values for all solenoids for a single PCM in a single CAN
 // message.
@@ -43,7 +42,6 @@
   friend class BufferedSolenoid;
 };
 
-}  // namespace wpilib
-}  // namespace frc971
+}  // namespace frc971::wpilib
 
 #endif  // FRC971_WPILIB_BUFFERED_PCM_H_