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/y2019/jevois/spi.h b/y2019/jevois/spi.h
index 62e5ea7..fd999de 100644
--- a/y2019/jevois/spi.h
+++ b/y2019/jevois/spi.h
@@ -14,8 +14,7 @@
 //
 // Our SPI transfers are fixed-size to simplify everything.
 
-namespace frc971 {
-namespace jevois {
+namespace frc971::jevois {
 
 constexpr size_t spi_transfer_size() {
   // The teensy->RoboRIO side is way bigger, so just calculate that.
@@ -33,7 +32,6 @@
 std::optional<RoborioToTeensy> SpiUnpackToTeensy(
     absl::Span<const char> transfer);
 
-}  // namespace jevois
-}  // namespace frc971
+}  // namespace frc971::jevois
 
 #endif  // Y2019_JEVOIS_SPI_H_