Fix coverity issues on branch 8.4 #396

Job	Run time
basic_clang	10s
basic_gcc	17s
check_update	1m 33s
check-ansi	2m 2s
address_ub_sanitizer	10m 55s
buildtest	7m 22s
EC_POINTs_api_test	18m 56s
enable_non-default_options	20s
external-test-pyca (1.51.0, 3.9)	1m 27s
fips_and_ktls	18s
legacy	3m 40s
memory_sanitizer	21m 5s
minimal	2m 10s
no-deprecated	16s
no-legacy	17s
no-shared (ubuntu-latest)	17s
non-caching	4m 22s
no-shared (macos-latest)	2m 58s
ntls_address_ub_sanitizer	9m 44s
ntls_memory_sanitizer	15m 39s
ntls-with-fips	17s
ntls-without-sm234	16s
out-of-source-and-install (ubuntu-latest)	19s
phe_test	12s
symbol_prefix-test	1m 9s
out-of-source-and-install (macos-latest)	3m 14s
threads_sanitizer	12s
ntls	10s
zkp-build-test	10s
	1h 49m 47s

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