examples/flow_filtering: add delay to wait link update
examples/flow_filtering: add delay to wait link update

Add up to 9s delay for getting link status to make sure NIC updates
link status successfully, just like other applications such as
testpmd and l2fwd.

Signed-off-by: Beilei Xing <7fb7e49de6d75fb4140bfcdada52e66859d93ebd@intel.com>
Acked-by: Ori Kam <dd654df5de18ba542acfaea52fe1a0799392087d@mellanox.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk