cmake HAVE_VSYSLOG examples

Geocld/PeaSyo third-party/json-c/CMakeLists.txt :218 

check_symbol_exists(vsyslog     "syslog.h" HAVE_VSYSLOG)

asset-group/5ghoul-5g-nr-attacks libs/libpcap/CMakeLists.txt :465 

check_function_exists(vsyslog HAVE_VSYSLOG)

ByConity/ByConity contrib/jsonc-cmake/CMakeLists.txt :214 

check_symbol_exists(vsyslog     "syslog.h" HAVE_VSYSLOG)

CTSRD-CHERI/cheribsd contrib/libpcap/CMakeLists.txt :756 

check_function_exists(vsyslog HAVE_VSYSLOG)