Don't check if the result of hasAttrSomewhere is non-zero in CallBase::getReturnedArgOperand()

[aeubanks]

Summary

Index is 0 when the return value has the returned attribute. But the
return value cannot have the returned attribute, so the check is
pointless.

[rnk]

lgtm

getArgOperand has an assert if you give it an OOB arg index, so this is at least checked.

llvm/lib/IR/Instructions.cpp

if (getRetDereferenceableBytes() > 0 &&
     return true;
 
   return false;
 }
 
 Value *CallBase::getReturnedArgOperand() const {
   unsigned Index;
 
-  if (Attrs.hasAttrSomewhere(Attribute::Returned, &Index) && Index)
+  if (Attrs.hasAttrSomewhere(Attribute::Returned, &Index))
     return getArgOperand(Index - AttributeList::FirstArgIndex);
   if (const Function *F = getCalledFunction())
-    if (F->getAttributes().hasAttrSomewhere(Attribute::Returned, &Index) &&
-        Index)
+    if (F->getAttributes().hasAttrSomewhere(Attribute::Returned, &Index))
       return getArgOperand(Index - AttributeList::FirstArgIndex);
 
   return nullptr;
 }
 
 /// Determine whether the argument or parameter has the given attribute.
 bool CallBase::paramHasAttr(unsigned ArgNo, Attribute::AttrKind Kind) const {
   assert(ArgNo < getNumArgOperands() && "Param index out of bounds!");