[NETLINK]: Use nlmsg_trim() where appropriate

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 84231ba..3d0a6cd 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -32,6 +32,8 @@
 #include <linux/rtnetlink.h>
 #include <linux/init.h>
 #include <linux/kmod.h>
+#include <linux/netlink.h>
+#include <net/netlink.h>
 #include <net/sock.h>
 #include <net/pkt_sched.h>
 #include <net/pkt_cls.h>
@@ -345,7 +347,7 @@
 
 nlmsg_failure:
 rtattr_failure:
-	skb_trim(skb, b - skb->data);
+	nlmsg_trim(skb, b);
 	return -1;
 }