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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209952 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/DataStream.cpp

@@ -68,7 +68,7 @@ public:
     if (Filename == "-") {
       Fd = 0;
       sys::ChangeStdinToBinary();
-      return error_code::success();
+      return error_code();
     }
 
     return sys::fs::openFileForRead(Filename, Fd);