Fix test

Author: smalyshev

ext/iconv/tests/bug76249.phpt

@@ -8,9 +8,11 @@ $fh = fopen('php://memory', 'rw');
 fwrite($fh, "abc");
 rewind($fh);
 stream_filter_append($fh, 'convert.iconv.ucs-2/utf8//IGNORE', STREAM_FILTER_READ, []);
-echo stream_get_contents($fh);
+$a = stream_get_contents($fh);
+var_dump(strlen($a));
 ?>
 DONE
 --EXPECTF--
 Warning: stream_get_contents(): iconv stream filter ("ucs-2"=>"utf8//IGNORE"): invalid multibyte sequence in %sbug76249.php on line %d
-慢DONE
+int(3)
+DONE