Fix coverity issues on branch 8.4 #411

Job	Run time
basic_clang	10s
basic_gcc	18s
check-ansi	2m 19s
address_ub_sanitizer	11m 4s
check_update	1m 40s
enable_non-default_options	16s
fips_and_ktls	18s
legacy	3m 35s
minimal	2m 5s
no-deprecated	16s
memory_sanitizer	18m 10s
no-legacy	18s
non-caching	4m 21s
no-shared (ubuntu-latest)	21s
no-shared (macos-latest)	2m 43s
ntls_address_ub_sanitizer	9m 36s
ntls_memory_sanitizer	15m 43s
symbol_prefix-test	1m 10s
threads_sanitizer	12s
buildtest	6m 42s
EC_POINTs_api_test	19m 26s
external-test-pyca (1.51.0, 3.9)	1m 22s
ntls	10s
ntls-with-fips	18s
ntls-without-sm234	18s
out-of-source-and-install (ubuntu-latest)	19s
out-of-source-and-install (macos-latest)	4m 1s
phe_test	16s
zkp-build-test	9s
	1h 47m 36s

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