Fix a typo in opcache func info for "get_parrent_class"

This should only have one r.
http://php.net/get_parent_class mentions that it returns string|false

Also, I'm not 100% sure if this is right - should this include
MAY_BE_NULL to handle the case of too many parameters?
(then again, get_called_class() also returns null in the global scope)

```
php > var_export(get_parent_class(2,3));
Warning: get_parent_class() expects at most 1 parameter, 2 given in php
shell code on line 1
NULL
```

0 files changed, 0 insertions, 0 deletions