net/pcap: fix resource leakage on port probe

net/pcap: fix resource leakage on port probe

When the port is probed, if the eth_from_pcaps function fails, the
previously opened pcap resources are not released, causing resource
leakage.

The patch solves the problem of resource leakage caused by abnormal
branch exit during the port probe process.

Fixes: 4c173302c307 ("pcap: add new driver")
Cc: stable@dpdk.org
Signed-off-by: Qiming Chen <chenqiming_huawei@163.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>