[CodeGen] Fix warning after #115531

Author: MaskRay

llvm/lib/CodeGen/MachineOperand.cpp

@@ -909,8 +909,8 @@ void MachineOperand::print(raw_ostream &OS, ModuleSlotTracker &MST,
     OS << printJumpTableEntryReference(getIndex());
     break;
   case MachineOperand::MO_GlobalAddress:
-    if (const auto *GV = getGlobal())
-      getGlobal()->printAsOperand(OS, /*PrintType=*/false, MST);
+    if (auto *GV = getGlobal())
+      GV->printAsOperand(OS, /*PrintType=*/false, MST);
     else // Invalid, but may appear in debugging scenarios.
       OS << "globaladdress(null)";