net/sched: use min() macro instead of doing it manually

Fix following coccicheck warnings:
./net/sched/cls_api.c:3333:17-18: WARNING opportunity for min()
./net/sched/cls_api.c:3389:17-18: WARNING opportunity for min()
./net/sched/cls_api.c:3427:17-18: WARNING opportunity for min()
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/cls_api.c

@@ -3330,7 +3330,7 @@ int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,
 	up_read(&block->cb_lock);
 	if (take_rtnl)
 		rtnl_unlock();
-	return ok_count < 0 ? ok_count : 0;
+	return min(ok_count, 0);
 }
 EXPORT_SYMBOL(tc_setup_cb_add);
 
@@ -3386,7 +3386,7 @@ int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp,
 	up_read(&block->cb_lock);
 	if (take_rtnl)
 		rtnl_unlock();
-	return ok_count < 0 ? ok_count : 0;
+	return min(ok_count, 0);
 }
 EXPORT_SYMBOL(tc_setup_cb_replace);
 
@@ -3424,7 +3424,7 @@ int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp,
 	up_read(&block->cb_lock);
 	if (take_rtnl)
 		rtnl_unlock();
-	return ok_count < 0 ? ok_count : 0;
+	return min(ok_count, 0);
 }
 EXPORT_SYMBOL(tc_setup_cb_destroy);