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/motors/fet12/fet12.cc b/motors/fet12/fet12.cc
index b6f2a45..61562be 100644
--- a/motors/fet12/fet12.cc
+++ b/motors/fet12/fet12.cc
@@ -12,8 +12,7 @@
 #include "motors/print/print.h"
 #include "motors/util.h"
 
-namespace frc971 {
-namespace motors {
+namespace frc971::motors {
 namespace {
 
 struct Fet12AdcReadings {
@@ -332,5 +331,4 @@
   return 0;
 }
 
-}  // namespace motors
-}  // namespace frc971
+}  // namespace frc971::motors
diff --git a/motors/fet12/fet12v2.cc b/motors/fet12/fet12v2.cc
index b0a0acc..9591331 100644
--- a/motors/fet12/fet12v2.cc
+++ b/motors/fet12/fet12v2.cc
@@ -14,8 +14,7 @@
 #include "motors/print/print.h"
 #include "motors/util.h"
 
-namespace frc971 {
-namespace motors {
+namespace frc971::motors {
 namespace {
 
 constexpr double Kv = 22000.0 * 2.0 * M_PI / 60.0 / 30.0 * 3.6;
@@ -718,5 +717,4 @@
   return 0;
 }
 
-}  // namespace motors
-}  // namespace frc971
+}  // namespace frc971::motors
diff --git a/motors/fet12/motor_controls.cc b/motors/fet12/motor_controls.cc
index 0ef7e3c..adc1839 100644
--- a/motors/fet12/motor_controls.cc
+++ b/motors/fet12/motor_controls.cc
@@ -2,8 +2,7 @@
 
 #include "motors/peripheral/configuration.h"
 
-namespace frc971 {
-namespace motors {
+namespace frc971::motors {
 namespace {
 
 template <int kRows, int kCols>
@@ -245,5 +244,4 @@
   return debug_[theta];
 }
 
-}  // namespace motors
-}  // namespace frc971
+}  // namespace frc971::motors
diff --git a/motors/fet12/power_wheels.cc b/motors/fet12/power_wheels.cc
index 893d92f..20453dc 100644
--- a/motors/fet12/power_wheels.cc
+++ b/motors/fet12/power_wheels.cc
@@ -11,8 +11,7 @@
 #include "motors/usb/usb.h"
 #include "motors/util.h"
 
-namespace frc971 {
-namespace motors {
+namespace frc971::motors {
 namespace {
 
 struct Fet12AdcReadings {
@@ -347,5 +346,4 @@
   return 0;
 }
 
-}  // namespace motors
-}  // namespace frc971
+}  // namespace frc971::motors