MySQL driver: Fix incorrect check for bad parameter in the
driver support for apr_dbd_transaction_end().

PR: 56330
Submitted by: Weiqiang Li <weiqiang_li hotmail.com>


git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@1625247 13f79535-47bb-0310-9956-ffa450edef68