Crash in dlp_VFSDirEntryEnumerate() when directory is empty -> signal SIGCHLD

```
dlp_VFSFileOpen(sd, volRef, rmAlbumDir, vfsModeReadWrite, &dirRef);
dlp_VFSDirEntryEnumerate(sd, dirRef, &itr, &dirItems, dirInfos);
```
Causes crash when directory on Palm device is empty ... contains no files.
With `jpilot -d` I only see `caught signal SIGCHLD` in the console.
