fail to get drmgr.dll's full path from its module data

_From [zhao...@google.com](https://code.google.com/u/106321947286816917100/) on March 20, 2013 18:28:14_

In event_module_load, drmgr.dll will be passed in as a module, however, the full_path is set "".

This is because the code @ get_all_module_short_names_uncached:

```
IF_CLIENT_INTERFACE({
if (path[0] == '\0' && is_in_client_lib(base))
path = get_client_path_from_addr(base);
});
```

0:000> dt base
Local var @ 0x2cea1c Type unsigned char*
0x71bb0000 "MZ???"

is_in_client_lib(base) check both client libraries and its aux libraries, including drmgr, so it return true.
However, get_client_path_from_addr(base) only check client libraries, which fail to see drmgr.dll

_Original issue: http://code.google.com/p/dynamorio/issues/detail?id=1127_