frameworks/rs: fix typos and clang-tidy warnings

This change fixes a few typos and clang tidy warnings related to the
"llvm-namespace-comment" checks.

Bug: 26936282
Test: WITH_TIDY=1 WITH_TIDY_CHECKS="llvm-namespace-comment" mm
Change-Id: Ic65182e5b4999fbd48d6a8ad7172e4bfeeb541f4
diff --git a/rsMesh.h b/rsMesh.h
index 6c60555..e0ce062 100644
--- a/rsMesh.h
+++ b/rsMesh.h
@@ -98,8 +98,8 @@
     }
 };
 
-}
-}
+} // namespace renderscript
+} // namespace android
 #endif //ANDROID_RS_MESH_H