Merge branch 'mlxsw-preparations-for-nexthop-objects-support-part-1-2'

Merge branch 'mlxsw-preparations-for-nexthop-objects-support-part-1-2'

Ido Schimmel says:

====================
mlxsw: Preparations for nexthop objects support - part 1/2

This patch set contains small and non-functional changes aimed at making
it easier to support nexthop objects in mlxsw. Follow up patches can be
found here [1].

Patches #1-#4 add a type field to the nexthop group struct instead of
the existing protocol field. This will be used later on to add a nexthop
object type, which can contain both IPv4 and IPv6 nexthops.

Patches #5-#7 move the IPv4 FIB info pointer (i.e., 'struct fib_info')
from the nexthop group struct to the route. The pointer will not be
available when the nexthop group is a nexthop object, but it needs to be
accessible to routes regardless.

Patch #8 is the biggest change, but it is an entirely cosmetic change
and should therefore be easy to review. The motivation and the change
itself are explained in detail in the commit message.

Patches #9-#12 perform small changes so that two functions that are
currently split between IPv4 and IPv6 could be consolidated in patches

Patch #15 removes an outdated comment.

[1] https://github.com/idosch/linux/tree/submit/nexthop_objects
====================

Link: https://lore.kernel.org/r/20201113160559.22148-1-idosch@idosch.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>