Merge branch 'netrom-cleanups'

Gustavo A. R. Silva says:

====================
netrom: refactor code and mark expected switch fall-throughs

The aim of this patchset is firstly to refactor code in nr_route.c in order to make it
easier to read and maintain and, secondly, to mark some expected switch fall-throughs
in preparation to enabling -Wimplicit-fallthrough.

I have to mention that I did not implement any unit test.
If someone has any suggestions on how I could test this piece of code
it'd be greatly appreciated.

Changes in v2:
 - Make use of the swap macro and remove inline keyword as suggested by
   Walter Harms and Kevin Dawson.

Changes in v3:
 - Update subject for both patches.
 - Add this cover letter as suggested by David Miller.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>