Convert: Remove HOME_OUTPUT enum value

Source/cmOutputConverter.cxx

@@ -52,9 +52,6 @@ std::string cmOutputConverter::ConvertToRelativePath(
   std::string result;
 
   switch (relative) {
-    case HOME_OUTPUT:
-      result = this->GetState()->GetBinaryDirectory();
-      break;
     case START_OUTPUT:
       result = this->StateSnapshot.GetDirectory().GetCurrentBinary();
       break;

Source/cmOutputConverter.h

@@ -40,7 +40,6 @@ public:
    */
   enum RelativeRoot
   {
-    HOME_OUTPUT,
     START_OUTPUT
   };
   enum OutputFormat