Use error_code() instead of error_code::succes()

There is no std::error_code::success, so this removes much of the noise
in transitioning to std::error_code.

llvm-svn: 209953
diff --git a/clang-tools-extra/modularize/Modularize.cpp b/clang-tools-extra/modularize/Modularize.cpp
index 93c0c4c..3e22b5f 100644
--- a/clang-tools-extra/modularize/Modularize.cpp
+++ b/clang-tools-extra/modularize/Modularize.cpp
@@ -284,7 +284,7 @@
     Dependencies[HeaderFileName.str()] = Dependents;
   }
 
-  return error_code::success();
+  return error_code();
 }
 
 // Helper function for finding the input file in an arguments list.