Merge branch 'l2tp-cleanup-socket-lookup-code'

Merge branch 'l2tp-cleanup-socket-lookup-code'

Guillaume Nault says:

====================
l2tp: cleanup socket lookup code in l2tp_ip and l2tp_ip6

First three patches remove redundant tests and add missing "const"
qualifiers.

Fourth patch splits the conditionals found in __l2tp_ip*_bind_lookup(),
to make these functions easier to review. In the process, I found that
some corner cases were still not handled properly. So I've added the
missing tests in this patch too, because they're pretty simple and the
whole "if" statements are modified anyway.

I expect it to be easier to review this way. If not, I can split up
patch #4, post the missing tests separately to -net, and later repost
this series as pure cleanup. Just let me know.
====================

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