ART: Add missing namespace comments

Add closing namespace comments.

Bug: 32619234
Test: m
Change-Id: I1f50e09dcd1038c4b540b87e5c19e319c1f592e4
diff --git a/runtime/openjdkjvmti/ti_thread.h b/runtime/openjdkjvmti/ti_thread.h
index c7f75d8..939aea7 100644
--- a/runtime/openjdkjvmti/ti_thread.h
+++ b/runtime/openjdkjvmti/ti_thread.h
@@ -37,7 +37,7 @@
 
 namespace art {
 class ArtField;
-}
+}  // namespace art
 
 namespace openjdkjvmti {