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/control_loops/control_loop.h b/frc971/control_loops/control_loop.h
index c02d094..500c81c 100644
--- a/frc971/control_loops/control_loop.h
+++ b/frc971/control_loops/control_loop.h
@@ -10,8 +10,7 @@
 #include "frc971/input/joystick_state_generated.h"
 #include "frc971/input/robot_state_generated.h"
 
-namespace frc971 {
-namespace controls {
+namespace frc971::controls {
 
 // Control loops run this often, "starting" at time 0.
 constexpr ::std::chrono::nanoseconds kLoopFrequency =
@@ -132,8 +131,7 @@
       SimpleLogInterval(kStaleLogInterval, ERROR, "no goal");
 };
 
-}  // namespace controls
-}  // namespace frc971
+}  // namespace frc971::controls
 
 #include "frc971/control_loops/control_loop-tmpl.h"  // IWYU pragma: export