gpgscm: Recover cells used to maintain interpreter state.
* tests/gpgscm/scheme.c (free_cell): New function. (free_cons): Likewise. (_s_return): Use the new function to recover cells used to save the state of the interpreter in 's_save'. This reduces the need to do a garbage collection considerably.
- Signed-off-by: Justus Winter <justus@g10code.com>