Merge branch 'sock_diag_destruction_events'

Craig Gallek says:

====================
Socket destruction events via netlink sock_diag

This series extends the netlink sock_diag interface to broadcast
socket information as they are being destroyed.  The current
interface is poll based and can not be used to retreive information
about sockets that are destroyed between poll intervals.

Only inet sockets are broadcast in this implementation, but other
families could easily be added as needed in the future.

If this patch set is accepted, a follow-up patch to the ss utility
in the iproute2 suite will also be submitted.
====================

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