cleanup

Author: fedor-miron

ydb/library/yql/providers/yt/provider/yql_yt_io_discovery.cpp

@@ -344,10 +344,14 @@ class TYtIODiscoveryTransformer : public TGraphTransformerBase {
             if (!res.Success()) {
                 PendingCanonizations_.clear();
                 PendingRanges_.clear();
-                PendingWalkFoldersKeys_.clear();
                 CanonizeFuture_ = {};
                 CanonizationRangesFoldersFuture_ = {};
 
+                PendingWalkFoldersKeys_.clear();
+                for (const auto& key : PendingWalkFoldersKeys_) {
+                    State_->WalkFoldersState.erase(key);
+                }
+
                 return TStatus::Error;
             }
         }