Fix use of "can_load()" in run_tests.pl.

CLA: Trivial

Fixes #3563.

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3564)
(cherry picked from commit 418bb7b3)