Fix incorrect error branch in ossl_bn_rsa_fips186_4_derive_prime()

Fix incorrect error branch in ossl_bn_rsa_fips186_4_derive_prime()

BN_priv_rand_range_ex() and BN_add() both return a 0 on failure and a 1
on success. In case of failure, the algorithm should fail. However, the
branch that it goes through on failure is "goto end", not "goto err".
Therefore, the algorithm will return 1 which indicates success instead
of 0 for failure, leading to potential problems for the callers.
Fix it by changing the goto to "goto err" instead of "goto end".

CLA: trivial

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
Reviewed-by: Todd Short <todd.short@me.com>
(Merged from https://github.com/openssl/openssl/pull/20279)