Merge branch 'devlink-port-attr-cleanup'

Parav Pandit says:

====================
devlink port attr cleanup

patch-1 removes the return 0 check at several places and simplfies
patch-2 constifies the attributes and moves the checks early
caller
====================

Link: https://patch.msgid.link/20250813094417.7269-1-parav@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>