If DCF representor port is closed after DCF port is closed, there will
be segmentation fault because representor accesses the released resource
of DCF port.
This patch checks if the resource is present before accessing.
Fixes: 5674465a32 ("net/ice: add DCF VLAN handling")
Cc: stable@dpdk.org
Signed-off-by: Dapeng Yu <dapengx.yu@intel.com>
Acked-by: Haiyue Wang <haiyue.wang@intel.com>