Merge branch 'ipmr-cleanups'

Nikolay Aleksandrov says:

====================
net: ipmr: cleanups and minor improvements

Since I'll have to work with ipmr, I decided to clean it up and do some
minor improvements. Functionally there're almost no changes except the
SLAB_PANIC removal. Most of the patches just re-design some functions to
be clearer and more concise and try to remove the ifdef web that was
inside. There's more information in each commit. This is the first set,
the end goal is to introduce complete netlink support and control over
the mfc and vif devices.
I've tried to test all of the setsockopt/getsockopt options, and also
made builds with various ipmr kconfig options turned on and off.

v2: change patch 7 to keep SLAB_PANIC and just drop the unnecessary null
check
====================

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