[TableGen] Eliminate dead code in ParseForeachDeclaration [NFC]

[Paul-C-Anagnostopoulos]

Summary

This little patch eliminates some dead code in ParseForEachDeclaration. It tested the TI variable for non-null, but after the function already returned on non-null.

[RKSimon]

LGTM - cheers

llvm/lib/TableGen/TGParser.cpp

default: {
     }
 
     if (TI) {
       if (ParseRangePiece(Ranges, TI))
         return nullptr;
       break;
     }
 
-    std::string Type;
-    if (TI)
-      Type = (Twine("' of type '") + TI->getType()->getAsString()).str();
-    Error(ValueLoc, "expected a list, got '" + I->getAsString() + Type + "'");
+    Error(ValueLoc, "expected a list, got '" + I->getAsString() + "'");
     if (CurMultiClass) {
       PrintNote({}, "references to multiclass template arguments cannot be "
                 "resolved at this time");
     }
     return nullptr;
   }
   }