[CodeGen] Remove unused variables in TargetLoweringBase.cpp (NFC)

llvm-project/llvm/lib/CodeGen/TargetLoweringBase.cpp:570:12: error: unused variable 'ModeN' [-Werror,-Wunused-variable]
  570 |   unsigned ModeN, ModelN;
      |            ^~~~~
llvm-project/llvm/lib/CodeGen/TargetLoweringBase.cpp:570:19: error: unused variable 'ModelN' [-Werror,-Wunused-variable]
  570 |   unsigned ModeN, ModelN;
      |                   ^~~~~~
2 errors generated.

Author: DamonFool

llvm/lib/CodeGen/TargetLoweringBase.cpp

@@ -567,7 +567,6 @@ RTLIB::Libcall RTLIB::getOutlineAtomicHelper(const Libcall (&LC)[5][4],
 
 RTLIB::Libcall RTLIB::getOUTLINE_ATOMIC(unsigned Opc, AtomicOrdering Order,
                                         MVT VT) {
-  unsigned ModeN, ModelN;
   if (!VT.isScalarInteger())
     return UNKNOWN_LIBCALL;
   uint64_t MemSize = VT.getScalarSizeInBits() / 8;