sched: domain sysctl fixes: add terminator comment

we had an incorrect-terminator bug in sd_alloc_ctl_domain_table()
before, so add a comment that documents it.
Signed-off-by: NMilton Miller <miltonm@bga.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

kernel/sched.c

@@ -5303,6 +5303,7 @@ sd_alloc_ctl_domain_table(struct sched_domain *sd)
 		sizeof(int), 0644, proc_dointvec_minmax);
 	set_table_entry(&table[10], "flags", &sd->flags,
 		sizeof(int), 0644, proc_dointvec_minmax);
+	/* &table[11] is terminator */
 
 	return table;
 }