app/testpmd: verify DCB config during forward config

app/testpmd: verify DCB config during forward config

Currently, the check for doing DCB test is assigned to
start_packet_forwarding(), which will be called when
run "start" cmd. But fwd_config_setup() is used in many
scenarios, such as, "port config all rxq".

This patch moves the check from start_packet_forwarding()
to fwd_config_setup().

Fixes: 7741e4cf16c0 ("app/testpmd: VMDq and DCB updates")
Cc: stable@dpdk.org
Signed-off-by: Huisong Li <lihuisong@huawei.com>
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Acked-by: Xiaoyun Li <xiaoyun.li@intel.com>