fix undefined variable in join-column section of xml driver

$name is undefined, It might be that the fix is as simple as foreach ($manyToOneElement->

{'join-columns'}->{'join-column'} as $name => $joinColumnElement) {
but I'm not sure

if (isset($manyToOneElement->{'join-column'})) {
$joinColumns[] = $this->_getJoinColumnMapping($manyToOneElement->{'join-column'});
} else if (isset($manyToOneElement->{'join-columns'}

)) {
foreach ($manyToOneElement->

{'join-columns'}

->

{'join-column'}

as $joinColumnElement) {
if (!isset($joinColumnElement['name']))

{ $joinColumnElement['name'] = $name; }

$joinColumns[] = $this->_getJoinColumnMapping($joinColumnElement);
}
}