Fix coverity issues on branch 8.4 #393

Job	Run time
basic_clang	11s
basic_gcc	19s
check_update	1m 4s
check-ansi	2m 5s
minimal	2m 9s
no-deprecated	18s
address_ub_sanitizer	11m 16s
buildtest	6m 47s
EC_POINTs_api_test	19m 2s
enable_non-default_options	17s
external-test-pyca (1.51.0, 3.9)	1m 27s
fips_and_ktls	17s
legacy	3m 38s
memory_sanitizer	23m 59s
no-legacy	17s
non-caching	4m 23s
no-shared (ubuntu-latest)	18s
ntls	9s
ntls_address_ub_sanitizer	9m 35s
no-shared (macos-latest)	2m 23s
ntls_memory_sanitizer	14m 41s
ntls-with-fips	17s
ntls-without-sm234	24s
out-of-source-and-install (ubuntu-latest)	22s
out-of-source-and-install (macos-latest)	3m 16s
symbol_prefix-test	1m 12s
phe_test	9s
threads_sanitizer	8s
zkp-build-test	10s
	1h 50m 33s

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