Fixed the logic for checking for PIs that start with 'xml'. It was doing doing...

Fixed the logic for checking for PIs that start with 'xml'. It was doing doing "if (stringICompare()) "
instead of "if (!stringICompare()).


git-svn-id: https://svn.apache.org/repos/asf/xerces/c/trunk@171461 13f79535-47bb-0310-9956-ffa450edef68