test: cmp_vfy_test: fix defined but unused

test: cmp_vfy_test: fix defined but unused

Building with

  ./config -DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION \
           -DPEDANTIC -Wall -Werror -pedantic

fails since the following test cases are excluded when
FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION is defined:

 - test_validate_msg_signature_srvcert_missing
 - test_validate_msg_mac_alg_protection_wrong
 - test_validate_msg_mac_alg_protection_missing

Guard the test cases by the corresponding preprocessor conditionals.

Signed-off-by: Čestmír Kalina <ckalina@redhat.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19868)