net: microchip: vcap: use kmemdup() to allocate memory

Use kmemdup() helper instead of open-coding to simplify
the code when allocating newckf and newcaf.

Generated by: scripts/coccinelle/api/memdup.cocci

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>
Link: https://lore.kernel.org/r/20230119092210.3607634-1-yangyingliang@huawei.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>