MDEV-17939 Assertion `++loop_count < 2' failed in trx_undo_report_rename

- During trx_undo_report_rename(), InnoDB can fail to write undo log
for it if undo log doesn't fit in the undo page. In that case, InnoDB
adds one more undo log page and retry to write the rename undo log.
But the assert is wrong and it doesn't allow to fail even for one time.

storage/innobase/trx/trx0rec.cc

@@ -1953,7 +1953,7 @@ dberr_t trx_undo_report_rename(trx_t* trx, const dict_table_t* table)
 		ut_ad((err == DB_SUCCESS) == !!block);
 
 		for (ut_d(int loop_count = 0); block;) {
-			ut_ad(++loop_count < 2);
+			ut_ad(loop_count++ < 2);
 			buf_block_dbg_add_level(block, SYNC_TRX_UNDO_PAGE);
 			ut_ad(undo->last_page_no == block->page.id.page_no());