stop_machine: struct cpu_stopper, remove alignment padding on 64 bits

Reorder elements in structure cpu_stopper to remove alignment padding on
64 bit builds, this shrinks its size from 40 to 32 bytes saving 8 bytes
per cpu.
Signed-off-by: NRichard Kennedy <richard@rsk.demon.co.uk>
Acked-by: NTejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kernel/stop_machine.c

@@ -35,9 +35,9 @@ struct cpu_stop_done {
 /* the actual stopper, one per every possible cpu, enabled on online cpus */
 struct cpu_stopper {
 	spinlock_t		lock;
+	bool			enabled;	/* is this stopper enabled? */
 	struct list_head	works;		/* list of pending works */
 	struct task_struct	*thread;	/* stopper thread */
-	bool			enabled;	/* is this stopper enabled? */
 };
 
 static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper);