[TargetInstrInfo] replace redundant expression in getMemOpBaseRegImmOfs

[mlemay-intel]

Summary

The expression for computing the return value of getMemOpBaseRegImmOfs has only
one possible value. The other value would result in a return earlier in the
function. This patch replaces the expression with its only possible value.

[sanjoy]

lgtm

lib/Target/X86/X86InstrInfo.cpp

bool X86InstrInfo::getMemOpBaseRegImmOfs(MachineInstr &MemOp, unsigned &BaseReg,
   const MachineOperand &DispMO = MemOp.getOperand(MemRefBegin + X86::AddrDisp);
 
   // Displacement can be symbolic
   if (!DispMO.isImm())
     return false;
 
   Offset = DispMO.getImm();
 
-  return MemOp.getOperand(MemRefBegin + X86::AddrIndexReg).getReg() ==
-         X86::NoRegister;
+  return true;
 }
 
 static unsigned getStoreRegOpcode(unsigned SrcReg,
                                   const TargetRegisterClass *RC,
                                   bool isStackAligned,
                                   const X86Subtarget &STI) {
   return getLoadStoreRegOpcode(SrcReg, RC, isStackAligned, STI, false);
 }