Delete dead variable.

llvm-svn: 264464
diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index 0080fab..61e80d5 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -1138,11 +1138,9 @@
   if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0]))
     goto error;
 
-  if (SavedMainFileBuffer) {
-    std::string ModName = getPreambleFile(this);
+  if (SavedMainFileBuffer)
     TranslateStoredDiagnostics(getFileManager(), getSourceManager(),
                                PreambleDiagnostics, StoredDiagnostics);
-  }
 
   if (!Act->Execute())
     goto error;