cmake HAVE_PCAP_WSOCKINIT examples

CTSRD-CHERI/cheribsd contrib/tcpdump/CMakeLists.txt :928 

check_function_exists(pcap_wsockinit HAVE_PCAP_WSOCKINIT)

CTSRD-CHERI/cheribsd contrib/tcpdump/CMakeLists.txt :931 

endif(NOT HAVE_PCAP_WSOCKINIT)