[Inliner] Fix a comment to match the code. NFC.

[haicheng]

Summary

TotalAltCost => TotalSecondaryCost

[davidxl]

lgtm

llvm/trunk/lib/Transforms/IPO/Inliner.cpp

if (!DisableInlinedAllocaMerging)
     mergeInlinedArrayAllocas(Caller, IFI, InlinedArrayAllocas, InlineHistory);
 
   return true;
 }
 
 /// Return true if inlining of CS can block the caller from being
 /// inlined which is proved to be more beneficial. \p IC is the
 /// estimated inline cost associated with callsite \p CS.
-/// \p TotalAltCost will be set to the estimated cost of inlining the caller
-/// if \p CS is suppressed for inlining.
+/// \p TotalSecondaryCost will be set to the estimated cost of inlining the
+/// caller if \p CS is suppressed for inlining.
 static bool
 shouldBeDeferred(Function *Caller, CallSite CS, InlineCost IC,
                  int &TotalSecondaryCost,
                  function_ref<InlineCost(CallSite CS)> GetInlineCost) {
 
   // For now we only handle local or inline functions.
   if (!Caller->hasLocalLinkage() && !Caller->hasLinkOnceODRLinkage())
     return false;