Replace llvm::error_code with std::error_code.

llvm-svn: 210783
diff --git a/llvm/unittests/Transforms/DebugIR/DebugIR.cpp b/llvm/unittests/Transforms/DebugIR/DebugIR.cpp
index 5860e31..c4ebc5c 100644
--- a/llvm/unittests/Transforms/DebugIR/DebugIR.cpp
+++ b/llvm/unittests/Transforms/DebugIR/DebugIR.cpp
@@ -57,7 +57,7 @@
 bool removeIfExists(StringRef Path) {
   // This is an approximation, on error we don't know in general if the file
   // existed or not.
-  llvm::error_code EC = sys::fs::remove(Path, false);
+  std::error_code EC = sys::fs::remove(Path, false);
   return EC != std::errc::no_such_file_or_directory;
 }