closes #5682, set dirty bit to 0 after cloning a rollback log node

git-svn-id: file:///svn/toku/tokudb@49932 c7de825b-a66e-492c-adef-691d508d4ae1

ft/rollback-ct-callbacks.cc

@@ -217,6 +217,8 @@ void toku_rollback_clone_callback(
     else {
         *cloned_value_data = &cloned_rollback;
     }
+    // clear the dirty bit, because the node has been cloned
+    log->dirty = 0;
     new_attr->is_valid = false;
 }