ecc: Fix possible memory leakage in parameter check of eddsa.
* cipher/ecc-eddsa.c (_gcry_ecc_eddsa_verify): Fix mem leak.
(cherry picked from commit 149ceb3cae03d0385341d32430aa5ae57de90007)
- GnuPG-bug-id: T4209
- Signed-off-by: Werner Koch <wk@gnupg.org>