cpusets: fix wrong domain attr updates

Fix wrong domain attr updates, or we will always update the first sched
domain attr.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>	[2.6.26.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/cpuset.c

@@ -679,7 +679,9 @@ static void rebuild_sched_domains(void)
 				if (apn == b->pn) {
 					cpus_or(*dp, *dp, b->cpus_allowed);
 					b->pn = -1;
-					update_domain_attr(dattr, b);
+					if (dattr)
+						update_domain_attr(dattr
+								   + nslot, b);
 				}
 			}
 			nslot++;