Remove useless check.

Hash can be longer than EC group degree and it will be truncated.

CLA: trivial

Reviewed-by: Paul Yang <yang.yang@baishancloud.com>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/7329)

(cherry picked from commit b770a80f6d0b08659cd03f26388b45512adb84f3)