Using pdump on test-pmd no longer works because of recent regression.
When new device is attached such as pdump using hotplug load pcap PMD;
testpmd now tries to configure it and gets all confused.

# ./build/app/dpdk-testpmd  -l 0-3 --vdev=net_tap0 -- -i
EAL: Detected CPU lcores: 20
EAL: Detected NUMA nodes: 1
EAL: Detected static linkage of DPDK
EAL: Multi-process socket /var/run/dpdk/rte/mp_socket
EAL: Selected IOVA mode 'VA'
Interactive-mode selected
testpmd: create a new mbuf pool <mb_pool_0>: n=171456, size=2176, socket=0
testpmd: preferred mempool ops selected: ring_mp_mc

Warning! port-topology=paired and odd forward ports number, the last port will
pair with itself.

Configuring Port 0 (socket 0)
Port 0: 4E:FB:7B:20:DA:C2
Checking link statuses...
Done
testpmd> Port 1 is probed. Now total ports is 2
Warning: NUMA should be configured manually by using --port-numa-config and
--ring-numa-config parameters along with --numa.
ETHDEV: The port (ID=1) is already configured
EAL: Error - exiting with code: 1
Error when negotiating Rx meta features on port 1: Device or resource busy

# ./build/app/dpdk-pdump -l 5 -- --pdump
'port=0,queue=*,rx-dev=/tmp/rx-pdump.pcap'
EAL: Detected CPU lcores: 20
EAL: Detected NUMA nodes: 1
EAL: Detected static linkage of DPDK
EAL: Multi-process socket /var/run/dpdk/rte/mp_socket_157372_1614979f4fed
EAL: Selected IOVA mode 'VA'
Port 1 MAC: 02 70 63 61 70 00
 core (5), capture for (1) tuples
 - port 0 device ((null)) queue 65535
Primary process is no longer active, exiting..