app/testpmd: fix invalid port detaching

The port was not validated before detaching.

Ignore port detach operation when the port is not valid.

Fixes: f8e5baa ("app/testpmd: check not detaching device twice")
Cc: stable@dpdk.org

Signed-off-by: Matan Azrad <matan@mellanox.com>
Acked-by: Bernard Iremonger <bernard.iremonger@intel.com>

app/test-pmd/testpmd.c

@@ -2557,6 +2557,9 @@ detach_port_device(portid_t port_id)
 
 	printf("Removing a device...\n");
 
+	if (port_id_is_invalid(port_id, ENABLED_WARN))
+		return;
+
 	dev = rte_eth_devices[port_id].device;
 	if (dev == NULL) {
 		printf("Device already removed\n");