Fix for HHVm issue with stream_get_meta_data

This should fix issue when HHVM is used, since HHVM has different implemenation of `tmpfile()` https://github.com/facebook/hhvm/issues/2336 that leads to returning empty `uri` key when `stream_get_meta_data` is used.

```
Warning: Filename cannot be empty in vendor/squizlabs/php_codesniffer/CodeSniffer/Reporting.php on line 237
```

```
array(10) {
  ["wrapper_type"]=>
  string(9) "plainfile"
  ["stream_type"]=>
  string(5) "STDIO"
  ["mode"]=>
  string(0) ""
  ["unread_bytes"]=>
  int(0)
  ["seekable"]=>
  bool(true)
  ["uri"]=>
  string(0) ""
  ["timed_out"]=>
  bool(false)
  ["blocked"]=>
  bool(true)
  ["eof"]=>
  bool(false)
  ["wrapper_data"]=>
  NULL
}
```