nfp: fix kdoc warnings on nested structures

Commit 84ce5b98 ("scripts: kernel-doc: improve nested logic to
handle multiple identifiers") improved the handling of nested structure
definitions in scripts/kernel-doc, and changed the expected format of
documentation.  This causes new warnings to appear on W=1 builds.

Only comment changes.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>