Merge branch 'neighbour-fix-update-of-proxy-neighbour'

Sabrina Dubroca says:

====================
neighbour: fix update of proxy neighbour

While re-reading some "old" patches I ran into a small change of
behavior in commit dc2a27e524ac ("neighbour: Update pneigh_entry in
pneigh_create().").

The old behavior was not consistent between ->protocol and ->flags,
and didn't offer a way to clear protocol, so maybe it's better to
change that (7-years-old [1]) behavior. But then we should change
non-proxy neighbours as well to keep neigh/pneigh consistent.

[1] df9b0e30d44c ("neighbor: Add protocol attribute")
====================

Link: https://patch.msgid.link/cover.1772894876.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>