sched: fix double kfree in failure path

It's not the responsibility of init_rootdomain() to free root_domain
allocated by alloc_rootdomain().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/sched.c

@@ -6970,7 +6970,7 @@ static int init_rootdomain(struct root_domain *rd, bool bootmem)
 	}
 
 	if (!alloc_cpumask_var(&rd->span, GFP_KERNEL))
-		goto free_rd;
+		goto out;
 	if (!alloc_cpumask_var(&rd->online, GFP_KERNEL))
 		goto free_span;
 	if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL))
@@ -6986,8 +6986,7 @@ static int init_rootdomain(struct root_domain *rd, bool bootmem)
 	free_cpumask_var(rd->online);
 free_span:
 	free_cpumask_var(rd->span);
-free_rd:
-	kfree(rd);
+out:
 	return -ENOMEM;
 }