cyignore sslSniffer due to main() conflicts

[petertorelli]

Description

When building for an embedded device, and wanting to include benchmark.c, one would use NO_MAIN_FUNCTION so that wolfcyrpt_benchmark_main() can be called from the application main(). However, sslSniffer/snifftest.c gates main() with NO_MAIN_DRIVER. So if I disable main() in snifftets.c, I lose wolfcrypt_benchmark_main() in benchmark.c. One solution would be to change benchmark.c to not block the wolfcrypt_benchmark_main function but that might impact more than just benchmark.c, so it is easier to just add another .cygnore for sslSniffer. It would be nice to have NO_SSLSNIFFER to exclude the entire sniffer, but again, that would touch code.

Testing

I built a simple PSOC6/PSOCEdge application and using NO_MAIN_FUNCTION + MAIN_NO_ARGS, I can easily link in the benchmarks without needing to change the github repo: it can be configured just with user_settings.h, and if I want a sniffer, I can use NO_CRYPT_BENCHMARK.

Checklist

• added tests
• updated/added doxygen
• updated appropriate READMEs
• Updated manual and documentation

NO_MAIN_FUNCTION and MAIN_NO_ARG are not documented, nor is .cyignore, so there's no place to update this. Also no tests for .cyignore.

[wolfSSL-Bot]

Can one of the admins verify this patch?