fix for 74x gcc491 IB

- This is a linux extension
- getcwd needs to be freed by free, not delete.

Citing the manual:

```
As  an  extension  to the POSIX.1-2001 standard, Linux (libc4, libc5, glibc) getcwd() allocates the buffer dynamically using malloc(3) if buf is NULL.  In
       this case, the allocated buffer has the length size unless size is zero, when buf is allocated as  big  as  necessary.   The  caller  should  free(3)  the
       returned buffer.
```

Please keep the original one. What is the issue with it?