net/pcap: fix memory leak in dumper open

net/pcap: fix memory leak in dumper open

In open_single_tx_pcap there is a call to pcap_open_dead which calls
malloc to create and return a pcap_t. That object is never freed in
this case. Other places it is freed by passing it back similar to the
way the pcap_dumper_t is in this case.

The pcap_t is only used to create the pcap_dumper_t and is never used
again so freeing it here is safe and much simpler than trying to pass
it back to be freed in eth_dev_stop along with the other
pcap_t/pcap_dumper_t objects.

Fixes: 4c173302c307 ("pcap: add new driver")
Cc: stable@dpdk.org
Signed-off-by: Stefan Baranoff <sbaranoff@gmail.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>