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/aos/ipc_lib/lockless_queue_stepping.cc b/aos/ipc_lib/lockless_queue_stepping.cc
index e819795..40d1631 100644
--- a/aos/ipc_lib/lockless_queue_stepping.cc
+++ b/aos/ipc_lib/lockless_queue_stepping.cc
@@ -25,9 +25,7 @@
 
 #ifdef SUPPORTS_SHM_ROBUSTNESS_TEST
 
-namespace aos {
-namespace ipc_lib {
-namespace testing {
+namespace aos::ipc_lib::testing {
 
 namespace {
 pid_t gettid() { return syscall(SYS_gettid); }
@@ -458,8 +456,6 @@
 
 pid_t SharedTid::Get() { return *tid_; }
 
-}  // namespace testing
-}  // namespace ipc_lib
-}  // namespace aos
+}  // namespace aos::ipc_lib::testing
 
 #endif  // SUPPORTS_SHM_ROBSTNESS_TEST