[clang-tidy] Cleanup namespace in utils folder.

Summary:
This is a step forward cleaning up the namespaces in clang-tidy/utils.
There is no behavior change.

Reviewers: alexfh

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D19819

llvm-svn: 268356
diff --git a/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.cpp b/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.cpp
index 3fe13bc..aa37c65 100644
--- a/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.cpp
+++ b/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.cpp
@@ -24,16 +24,16 @@
   if (Var.getLocation().isMacroID())
     return;
 
-  Diagnostic << utils::create_fix_it::changeVarDeclToReference(Var, Context);
+  Diagnostic << utils::fixit::changeVarDeclToReference(Var, Context);
   if (!Var.getType().isLocalConstQualified())
-    Diagnostic << utils::create_fix_it::changeVarDeclToConst(Var);
+    Diagnostic << utils::fixit::changeVarDeclToConst(Var);
 }
 
 } // namespace
 
 
 using namespace ::clang::ast_matchers;
-using decl_ref_expr_utils::isOnlyUsedAsConst;
+using utils::decl_ref_expr::isOnlyUsedAsConst;
 
 void UnnecessaryCopyInitialization::registerMatchers(MatchFinder *Finder) {
   auto ConstReference = referenceType(pointee(qualType(isConstQualified())));