net/sched: Remove unnecessary if statement

It has been deal with the 'if (err' statement in rtnetlink_send()
and rtnl_unicast(). so remove unnecessary if statement.

v2: use the raw name rtnetlink_send().

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index d73b5c5..c8cb59a 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1870,13 +1870,10 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb,
 	}
 
 	if (unicast)
-		err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
+		err = rtnl_unicast(skb, net, portid);
 	else
 		err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 				     n->nlmsg_flags & NLM_F_ECHO);
-
-	if (err > 0)
-		err = 0;
 	return err;
 }
 
@@ -1909,15 +1906,13 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 	}
 
 	if (unicast)
-		err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
+		err = rtnl_unicast(skb, net, portid);
 	else
 		err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 				     n->nlmsg_flags & NLM_F_ECHO);
 	if (err < 0)
 		NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");
 
-	if (err > 0)
-		err = 0;
 	return err;
 }
 
@@ -2711,13 +2706,11 @@ static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
 	}
 
 	if (unicast)
-		err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
+		err = rtnl_unicast(skb, net, portid);
 	else
 		err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 				     flags & NLM_F_ECHO);
 
-	if (err > 0)
-		err = 0;
 	return err;
 }
 
@@ -2741,7 +2734,7 @@ static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
 	}
 
 	if (unicast)
-		return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
+		return rtnl_unicast(skb, net, portid);
 
 	return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
 }