[llvm-objdump] Ensure we consistently use the llvm::stable_sort wrappers.

We use this everywhere else in this file, these were just missed.

Author: RKSimon

llvm/tools/llvm-objdump/llvm-objdump.cpp

@@ -1737,8 +1737,8 @@ static void disassembleObject(const Target *TheTarget, const ObjectFile *Obj,
   // the output.
   StringSet<> FoundDisasmSymbolSet;
   for (std::pair<const SectionRef, SectionSymbolsTy> &SecSyms : AllSymbols)
-    stable_sort(SecSyms.second);
-  stable_sort(AbsoluteSymbols);
+    llvm::stable_sort(SecSyms.second);
+  llvm::stable_sort(AbsoluteSymbols);
 
   std::unique_ptr<DWARFContext> DICtx;
   LiveVariablePrinter LVP(*Ctx.getRegisterInfo(), *STI);