A static const variable is implicitly zero initialized

A static const variable is implicitly zero initialized

Older clang versions complain about the explicit initializer
because the first member of the struct is a struct.
But it is not necessary to explicitly initialize it anyway.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19284)