Add the folowing to your themes’s functions.php file.
add_action( 'wp_login', 'wpse_112895_validate_user', 10, 2 );
function wpse_112895_validate_user( $login, $user ) {
$meta = get_user_meta( $user->ID, 'adminveri', true );
// not verified, log them out!
if ( $meta != 0 )
wp_logout();
}