Plug leak in ec_key_create()

Plug leak in ec_key_create()

EVP_PKEY_set1_EC_KEY() bumps the refcount of eckey, so eckey won't be
freed at the end of keyproc() or acctproc(), which means that secrets
aren't wiped. Move EC_KEY_free() to the out label, so that the refcount
is decremented or the key freed, as appropriate.

tested/ok claudio