net/mlx5: fix exception handling
net/mlx5: fix exception handling

A sanity check is required in priv_fdir_disable(). If resizing Rx queue
fails, this can cause a crash by referencing a NULL pointer.

Fixes: 76f5c99e6840 ("mlx5: support flow director")
Fixes: 0cdddf4d0626 ("net/mlx5: split Rx queue structure")
Cc: stable@dpdk.org

Signed-off-by: Yongseok Koh <76b37c91816d73ef9cf709e3e83a68f2d162f1e2@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