[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/act_simple.c b/net/sched/act_simple.c
index ecbcfa5..36e1eda 100644
--- a/net/sched/act_simple.c
+++ b/net/sched/act_simple.c
@@ -16,6 +16,7 @@
 #include <linux/netdevice.h>
 #include <linux/skbuff.h>
 #include <linux/rtnetlink.h>
+#include <net/netlink.h>
 #include <net/pkt_sched.h>
 
 #define TCA_ACT_SIMP 22
@@ -173,7 +174,7 @@
 	return skb->len;
 
 rtattr_failure:
-	skb_trim(skb, b - skb->data);
+	nlmsg_trim(skb, b);
 	return -1;
 }