change /var/spool/abrt/ to /var/tmp/abrt rhbz#912750

- note: /var/spool/abrt-upload is still ok, the data is moved
  to /var/tmp/abrt/ after it's processed

Signed-off-by: Jiri Moskovcak <jmoskovc@redhat.com>
Signed-off-by: Jakub Filak <jfilak@redhat.com>