[RISCV] Remove duplicate check in an if statement. NFC

Author: topperc

llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp

@@ -2864,7 +2864,7 @@ bool RISCVDAGToDAGISel::SelectAddrRegImm(SDValue Addr, SDValue &Base,
 
   if (CurDAG->isBaseWithConstantOffset(Addr)) {
     int64_t CVal = cast<ConstantSDNode>(Addr.getOperand(1))->getSExtValue();
-    if (isInt<12>(CVal) && isInt<12>(CVal)) {
+    if (isInt<12>(CVal)) {
       Base = Addr.getOperand(0);
       if (Base.getOpcode() == RISCVISD::ADD_LO) {
         SDValue LoOperand = Base.getOperand(1);