MDEV-15217 Assertion `thd->transaction.xid_state.xid.is_null()' failed

in trans_xa_start.

        test fixed.

mysql-test/r/xa.result

@@ -282,7 +282,6 @@ INSERT INTO t1 SELECT * FROM t2;
 connection default;
 REPLACE INTO t2 SELECT * FROM t2;
 connection con1;
-ERROR 40001: Deadlock found when trying to get lock; try restarting transaction
 disconnect con1;
 connect  con2,localhost,root,,test;
 INSERT INTO t3 VALUES (1);

mysql-test/t/xa.test

@@ -414,7 +414,7 @@ INSERT INTO t1 SELECT * FROM t2;
 REPLACE INTO t2 SELECT * FROM t2;
 
 --connection con1
---error ER_LOCK_DEADLOCK
+--error 0, ER_LOCK_DEADLOCK, ER_LOCK_WAIT_TIMEOUT
 --reap
 --disconnect con1