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/dlqr.h b/frc971/control_loops/dlqr.h
index 48e8474..57aa88b 100644
--- a/frc971/control_loops/dlqr.h
+++ b/frc971/control_loops/dlqr.h
@@ -3,8 +3,7 @@
 
 #include <Eigen/Dense>
 
-namespace frc971 {
-namespace controls {
+namespace frc971::controls {
 
 template <int num_states, int num_inputs>
 int Controllability(const ::Eigen::Matrix<double, num_states, num_states> &A,
@@ -114,7 +113,6 @@
   return INFO;
 }
 
-}  // namespace controls
-}  // namespace frc971
+}  // namespace frc971::controls
 
 #endif  // FRC971_CONTROL_LOOPS_DLQR_H_