cmake HAVE_PCAP_FREE_DATALINKS examples

usb-tools/USBProxy-legacy src/cmake/modules/FindPCAP.cmake :119 

CHECK_FUNCTION_EXISTS("pcap_free_datalinks" HAVE_PCAP_FREE_DATALINKS)

boundary/wireshark cmake/modules/FindPCAP.cmake :128 

CHECK_FUNCTION_EXISTS("pcap_free_datalinks" HAVE_PCAP_FREE_DATALINKS)

CTSRD-CHERI/cheribsd contrib/tcpdump/CMakeLists.txt :792 

check_function_exists(pcap_free_datalinks HAVE_PCAP_FREE_DATALINKS)