Follow-up fix for MDEV-12352: Plug a memory leak

trx_rollback_active(): When aborting the rollback, free the query graph.

storage/innobase/trx/trx0roll.cc

@@ -579,6 +579,8 @@ trx_rollback_active(
 		ut_ad(!srv_undo_sources);
 		ut_ad(srv_fast_shutdown);
 		ut_ad(!dictionary_locked);
+		que_graph_free(static_cast<que_t*>(
+				       roll_node->undo_thr->common.parent));
 		goto func_exit;
 	}
 

storage/xtradb/trx/trx0roll.cc

@@ -579,6 +579,8 @@ trx_rollback_active(
 		ut_ad(!srv_undo_sources);
 		ut_ad(srv_fast_shutdown);
 		ut_ad(!dictionary_locked);
+		que_graph_free(static_cast<que_t*>(
+				       roll_node->undo_thr->common.parent));
 		goto func_exit;
 	}