cgroup: clean up if condition in cgroup_pidlist_start()

There's no need to use '<=' when knowing 'l->list[mid] != pid' already.
No functional change intended.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

kernel/cgroup/cgroup-v1.c

@@ -431,7 +431,7 @@ static void *cgroup_pidlist_start(struct seq_file *s, loff_t *pos)
 			if (l->list[mid] == pid) {
 				index = mid;
 				break;
-			} else if (l->list[mid] <= pid)
+			} else if (l->list[mid] < pid)
 				index = mid + 1;
 			else
 				end = mid;