tests: Fix memory leak.
* tests/basic.c (check_gost28147_cipher): Free cipher handles.
Backport from master commit: 5530a8234d703ce9b685f78fb6e951136eb0aeb2
- Fixes-commit: 4f5c26c73c66daf2e4aff966e43c22b2db7e0138
- Signed-off-by: Justus Winter <justus@g10code.com>