Description:
------------
PDO/MySQL getColumnMeta() always returns bool(false) in pdo_mysql due to a bogus check

Reproduce code:
---------------
the following sourcecode:

<?php
  $dbh= new PDO('mysql:host='.$argv[1], $argv[2], $argv[3]); 

  $stmt= $dbh->prepare('select * from entries where id = :id');
  $stmt->bindParam(':id', $argv[4]);
  if (!$stmt->execute()) {
    var_dump($dbh->errorInfo());
    exit;
  }

  for ($i= 0, $s= $stmt->columnCount(); $i < $s; $i++) {
    echo $i, ':: '; var_dump($stmt->getColumnMeta($i));
  }
?>

Expected result:
----------------
0:: array(6) {
  ["native_type"]=>
  string(4) "LONG"
  ["flags"]=>
  array(2) {
    [0]=>
    string(8) "not_null"
    [1]=>
    string(11) "primary_key"
  }
  ["name"]=>
  string(2) "id"
  ["len"]=>
  int(11)
  ["precision"]=>
  int(0)
  ["pdo_type"]=>
  int(2)
}
1:: array(6) {
  ["native_type"]=>
  string(10) "VAR_STRING"
  ["flags"]=>
  array(0) {
  }
  ["name"]=>
  string(5) "title"
  ["len"]=>
  int(200)
  ["precision"]=>
  int(0)
  ["pdo_type"]=>
  int(2)
}
[...and so on...]

Actual result:
--------------
1:: bool(false)
2:: bool(false)
[...and so on...]