Fix cpplint whitespace/comments issues

Change-Id: Iae286862c85fb8fd8901eae1204cd6d271d69496
diff --git a/compiler/driver/dex_compilation_unit.cc b/compiler/driver/dex_compilation_unit.cc
index 6ba338a..eb8941b 100644
--- a/compiler/driver/dex_compilation_unit.cc
+++ b/compiler/driver/dex_compilation_unit.cc
@@ -60,4 +60,4 @@
   return symbol_;
 }
 
-} // namespace art
+}  // namespace art