Clean up interface to getGlobalLinkName.

llvm-svn: 31001
diff --git a/llvm/lib/CodeGen/DwarfWriter.cpp b/llvm/lib/CodeGen/DwarfWriter.cpp
index 1c52c5b..1d08d07 100644
--- a/llvm/lib/CodeGen/DwarfWriter.cpp
+++ b/llvm/lib/CodeGen/DwarfWriter.cpp
@@ -1634,8 +1634,7 @@
   AddSourceLine(VariableDie, UnitDesc, GVD->getLine());
   
   // Work up linkage name.
-  std::string LinkageName;
-  Asm->getGlobalLinkName(GV, LinkageName);
+  const std::string LinkageName = Asm->getGlobalLinkName(GV);
 
   // Add address.
   DIEBlock *Block = new DIEBlock();