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/usb/cdc.h b/motors/usb/cdc.h
index f8f084b..e10dbf0 100644
--- a/motors/usb/cdc.h
+++ b/motors/usb/cdc.h
@@ -13,8 +13,7 @@
 // lot of formats. The only commonality across the "class" seems to be some
 // constants and a few descriptors.
 
-namespace frc971 {
-namespace teensy {
+namespace frc971::teensy {
 
 struct CdcLineCoding {
   static constexpr uint8_t stop_bits_1() { return 0; }
@@ -129,7 +128,6 @@
   uint16_t control_line_state_ = 0;
 };
 
-}  // namespace teensy
-}  // namespace frc971
+}  // namespace frc971::teensy
 
 #endif  // MOTORS_USB_CDC_H_