Eliminate unnecessary empty string literals.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110183 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp
index 6cae804..8313de5 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp
@@ -199,7 +199,7 @@
 #else
   errs() << "SelectionDAG::getGraphAttrs is only available in debug builds"
          << " on systems with Graphviz or gv!\n";
-  return std::string("");
+  return std::string();
 #endif
 }