Based on an initial patch from Oleg Nesterov <oleg@tv-sign.ru>

rcu_data.last_qsctr is not needed.  Actually, not even a counter is needed,
just a flag that indicates that there was a quiescent state.
Signed-Off-By: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>