sched: Remove unused variable in 'struct sched_domain'

The 'u64 last_update' variable isn't used now, remove it to save a bit of space.
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Morten.Rasmussen@arm.com
Cc: linaro-kernel@lists.linaro.org
Link: http://lkml.kernel.org/r/1384852912-24791-1-git-send-email-alex.shi@linaro.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

include/linux/sched.h

@@ -823,8 +823,6 @@ struct sched_domain {
 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
 	unsigned int nr_balance_failed; /* initialise to 0 */
 
-	u64 last_update;
-
 	/* idle_balance() stats */
 	u64 max_newidle_lb_cost;
 	unsigned long next_decay_max_lb_cost;