Merge branch 'nexthop-various-cleanups'

Ido Schimmel says:

====================
nexthop: Various cleanups

Benefit from recent bug fixes and simplify the nexthop dump code.

No regressions in existing tests:

 # ./fib_nexthops.sh
 [...]
 Tests passed: 234
 Tests failed:   0
====================

Link: https://lore.kernel.org/r/20230813164856.2379822-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>