You could use that code to set a session variable and then use the session variable as the trigger for the MySQLi authenticate.
So:
1) Create a recordset filtered by the entered email address
2) Then use your code to validate the password returned with this code:
$storedpassword = $yourRecordset->getColumnVal('paswordColumn');
$inputpassword = ((isset($_POST["password"]))?$_POST["password"]:"") ;
@session_start();
if (password_verify($inputpassword, $storedpassword)) {
$_SESSION['auth_trigger'] = "passed";
} else {
$_SESSION['auth_trigger'] = "";
}
3) then set your MySQLi login trigger to: $_SESSION['auth_trigger'], only use the email address for the login filter.