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/motors/print/itm.h b/motors/print/itm.h
index 64e3092..05ffb2c 100644
--- a/motors/print/itm.h
+++ b/motors/print/itm.h
@@ -5,8 +5,7 @@
 
 #include "motors/print/print.h"
 
-namespace frc971 {
-namespace motors {
+namespace frc971::motors {
 
 // A printing implementation via the SWO (trace output) pin. This requires an
 // attached debugger which is in SWD (Single Wire Debug) mode, has the SWO
@@ -28,7 +27,6 @@
   int WriteDebug(absl::Span<const char> buffer) override;
 };
 
-}  // namespace motors
-}  // namespace frc971
+}  // namespace frc971::motors
 
 #endif  // MOTORS_PRINT_ITM_
diff --git a/motors/print/semihosting.h b/motors/print/semihosting.h
index 6094a67..e04a4e5 100644
--- a/motors/print/semihosting.h
+++ b/motors/print/semihosting.h
@@ -5,8 +5,7 @@
 
 #include "motors/print/print.h"
 
-namespace frc971 {
-namespace motors {
+namespace frc971::motors {
 
 // A printing implementation which uses the ARM semihosting interface. This
 // requries an attached debugger with software support.
@@ -31,7 +30,6 @@
   // file if the name is filled out in the parameters.
 };
 
-}  // namespace motors
-}  // namespace frc971
+}  // namespace frc971::motors
 
 #endif  // MOTORS_PRINT_SEMIHOSTING_H_
diff --git a/motors/print/uart.h b/motors/print/uart.h
index 7d81577..e223ae7 100644
--- a/motors/print/uart.h
+++ b/motors/print/uart.h
@@ -4,8 +4,7 @@
 #include "motors/peripheral/uart.h"
 #include "motors/print/print.h"
 
-namespace frc971 {
-namespace motors {
+namespace frc971::motors {
 
 // A printing implementation using a hardware UART. This has a reasonably sized
 // buffer in memory and uses interrupts to keep the hardware busy. It could
@@ -28,7 +27,6 @@
 // Could easily create a subclass of UartPrinting that also implements
 // WriteDebug on a second UART, and conditionally instantiate that.
 
-}  // namespace motors
-}  // namespace frc971
+}  // namespace frc971::motors
 
 #endif  // MOTORS_PRINT_UART_H_
diff --git a/motors/print/usb.h b/motors/print/usb.h
index c2224d2..5e811b3 100644
--- a/motors/print/usb.h
+++ b/motors/print/usb.h
@@ -5,8 +5,7 @@
 #include "motors/usb/cdc.h"
 #include "motors/usb/usb.h"
 
-namespace frc971 {
-namespace motors {
+namespace frc971::motors {
 
 // A printing implementation which uses externally-created functions. The stdout
 // one is required, while the debug one is optional.
@@ -68,7 +67,6 @@
   teensy::AcmTty debug_tty_;
 };
 
-}  // namespace motors
-}  // namespace frc971
+}  // namespace frc971::motors
 
 #endif  // MOTORS_PRINT_USB_H_