net: marvell: prestera: remove reduntant code

Fixes the coverity warning 'EVALUATION_ORDER' violation. port is written
twice with the same value.

Signed-off-by: Sebin Sebastian <mailmesebin00@gmail.com>
Link: https://lore.kernel.org/r/20220801040731.34741-1-mailmesebin00@gmail.com


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