[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>

net/sched/cls_u32.c

@@ -50,6 +50,7 @@
 #include <linux/notifier.h>
 #include <linux/rtnetlink.h>
 #include <net/ip.h>
+#include <net/netlink.h>
 #include <net/route.h>
 #include <linux/skbuff.h>
 #include <net/sock.h>
@@ -772,7 +773,7 @@ static int u32_dump(struct tcf_proto *tp, unsigned long fh,
 	return skb->len;
 
 rtattr_failure:
-	skb_trim(skb, b - skb->data);
+	nlmsg_trim(skb, b);
 	return -1;
 }