[llvm-readobj] Fix formatting of unknown note types

llvm-svn: 357221
diff --git a/llvm/tools/llvm-readobj/ELFDumper.cpp b/llvm/tools/llvm-readobj/ELFDumper.cpp
index 2d5a306..d2fb2c3 100644
--- a/llvm/tools/llvm-readobj/ELFDumper.cpp
+++ b/llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -4704,7 +4704,8 @@
       if (!N.Type.empty())
         W.printString(N.Type, N.Value);
     } else {
-      W.getOStream() << "Unknown note type: (" << format_hex(Type, 10) << ')';
+      W.printString("Type",
+                    "Unknown (" + to_string(format_hex(Type, 10)) + ")");
     }
   };