net/mlx5: fix crash in device probe
net/mlx5: fix crash in device probe

This patch initializes counter descriptor struct before invoking Verbs
api to avoid segmentation fault.

Fixes: 9a761de8ea14 ("net/mlx5: flow counter support")
Cc: stable@dpdk.org

Signed-off-by: Xueming Li <a578f76ca98b1dec92e0d1baef814b93f3f2f3b4@mellanox.com>
Acked-by: Adrien Mazarguil <9d39ea493ca46c560334f650ac5d4b5ffbcb5cf0@6wind.com>

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