cmake HAVE_RTE_ETH_DEV_COUNT_AVAIL examples

asset-group/5ghoul-5g-nr-attacks libs/libpcap/CMakeLists.txt :1593 

check_function_exists(rte_eth_dev_count_avail HAVE_RTE_ETH_DEV_COUNT_AVAIL)

CTSRD-CHERI/cheribsd contrib/libpcap/CMakeLists.txt :2350 

check_function_exists(rte_eth_dev_count_avail HAVE_RTE_ETH_DEV_COUNT_AVAIL)