If unable to create tmp. file on disk then return LTO_WRITE_FAILURE status.

llvm-svn: 29844
diff --git a/llvm/tools/lto/lto.cpp b/llvm/tools/lto/lto.cpp
index 372e6ea..a737953 100644
--- a/llvm/tools/lto/lto.cpp
+++ b/llvm/tools/lto/lto.cpp
@@ -298,7 +298,7 @@
   std::string ErrMsg;
   if (tmpAsmFilePath.createTemporaryFileOnDisk(&ErrMsg)) {
     std::cerr << "lto: " << ErrMsg << "\n";
-    return;
+    return LTO_WRITE_FAILURE;
   }
   sys::RemoveFileOnSignal(tmpAsmFilePath);