Fix crash while reading metadata

blockstore_init.cpp

@@ -80,15 +80,14 @@ int blockstore_init_meta::loop()
 
 void blockstore_init_meta::handle_entries(struct clean_disk_entry* entries, int count, int block_order)
 {
-    auto end = bs->clean_db.end();
     for (unsigned i = 0; i < count; i++)
     {
         if (entries[i].oid.inode > 0)
         {
             auto clean_it = bs->clean_db.find(entries[i].oid);
-            if (clean_it == end || clean_it->second.version < entries[i].version)
+            if (clean_it == bs->clean_db.end() || clean_it->second.version < entries[i].version)
             {
-                if (clean_it != end)
+                if (clean_it != bs->clean_db.end())
                 {
                     // free the previous block
                     allocator_set(bs->data_alloc, clean_it->second.version >> block_order, false);