Remove redundant ASN1_INTEGER_set call

This trivial patch removes a duplicated call to ASN1_INTEGER_set.

Fixes Issue #6977

Signed-off-by: Eric Brown <browne@vmware.com>

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/6984)