According to docs, EVP_PKEY_get_int_param should return 1 on Success, and
0 on Failure. So, fix checking of this return value at check_curve
CLA: trivial
Reviewed-by: Todd Short <todd.short@me.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20770)