Relax the feed_nodes collection check, which triggers a false positiv…

…e in some modes where the feed node collection is auto-generated. Keep it as a warning to help correct user-provided feed node lists.

PiperOrigin-RevId: 168396408

tensorflow/core/grappler/costs/virtual_scheduler.cc

@@ -229,8 +229,9 @@ Status VirtualScheduler::Init() {
     return Status(error::UNAVAILABLE, "No ready nodes in the graph.");
   }
 
-  CHECK(feed_nodes.empty()) << "Some feed nodes were not found in the graph: "
-                            << str_util::Join(feed_nodes, ",");
+  if (!feed_nodes.empty())
+    LOG(ERROR) << "Some feed nodes were not found in the graph: "
+               << str_util::Join(feed_nodes, ",");
 
   initialized_ = true;
   return Status::OK();