g10: Fix secmem leak.
* g10/keygen.c (proc_parameter_file): Fix secmem leak.
proc_parameter_file adds certain parameters to the list in the PARA
argument; however, these new entries are leaked because they
are added to head, while the PARA list is released by the caller
of proc_parameter_file.
- GnuPG-bug-id: T1371
- Signed-off-by: Ineiev <ineiev@gnu.org>