Fix cpplint's whitespace warnings.

Change-Id: I16b69d773e59b49e8e30227b5aa5cb1959a8930f
diff --git a/src/offsets.cc b/src/offsets.cc
index 500e17e..49e52fb 100644
--- a/src/offsets.cc
+++ b/src/offsets.cc
@@ -10,4 +10,4 @@
   return os << offs.Int32Value();
 }
 
-}
+}  // namespace art