Merge branch 'tcp-up-pin-tw-timer'

Florian Westphal says:

====================
net: tcp: un-pin tw timer

Changes since previous iteration:
 - Patch 1: update a comment, I copied Erics v7 RvB tag.
 - Patch 2: move bh off/on into hashdance_schedule and get rid of
   comment mentioning pinned tw timer.
   I did not copy Erics RvB tag over from v7 because of the change.
 - Patch 3 is unchanged, so I kept Erics RvB tag.

This is v8 of the series where the tw_timer is un-pinned to get rid of
interferences in isolated CPUs setups.

First patch makes necessary preparations, existing code relies on
TIMER_PINNED to avoid races.

Second patch un-pins the TW timer. Could be folded into the first one,
but it might help wrt. bisection.

Third patch is a minor cleanup to move a helper from .h to the only
remaining compilation unit.

Tested with iperf3 and stress-ng socket mode.
====================

Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>