remove unnecessary null checks

remove unnecessary null checks

Found by nullfree.cocci.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
[David: for lpm parts:]
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Acked-by: Vladimir Medvedkin <vladimir.medvedkin@intel.com>
[David: for vdpa/mlx5 parts:]
Acked-by: Matan Azrad <matan@nvidia.com>
[David: for dma/dpaa2, raw/ifpga, vdpa/mlx5:]
Acked-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
Reviewed-by: Chengwen Feng <fengchengwen@huawei.com>
[David: reran cocci.sh and updated common/mlx5 and cryptodev asym test]
Signed-off-by: David Marchand <david.marchand@redhat.com>