comedi_open has file descriptor leak

comedi_open has file descriptor leak

If something fails after a succesful open, cleanup fails to close the file.

The code

   cleanup:
         if(it)
                 free(it);

needs to be replaced with something like:

   cleanup:
         if (it) {
           if (it->fd >= 0) {
             close(it->fd);
           }
         free(it);

Regards

Anders Blomdell