sched: Fix memory leakage in build_sched_groups()

In build_sched_groups() we don't need to call get_group() for cpus
which are already covered in previous iterations. Calling get_group()
would mark the group used and eventually leak it since we wouldn't
connect it and not find it again to free it.

This will happen only in cases where sg->cpumask contained more than
one cpu (For any topology level). This patch would free sg's memory
for all cpus leaving the group leader as the group isn't marked used
now.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/7a61e955abdcbb1dfa9fe493f11a5ec53a11ddd3.1370948150.git.viresh.kumar@linaro.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/core.c

@@ -5357,12 +5357,12 @@ build_sched_groups(struct sched_domain *sd, int cpu)
 
 	for_each_cpu(i, span) {
 		struct sched_group *sg;
-		int group = get_group(i, sdd, &sg);
-		int j;
+		int group, j;
 
 		if (cpumask_test_cpu(i, covered))
 			continue;
 
+		group = get_group(i, sdd, &sg);
 		cpumask_clear(sched_group_cpus(sg));
 		sg->sgp->power = 0;
 		cpumask_setall(sched_group_mask(sg));