Network Drop Monitor: Add trace declaration for skb frees

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>

 include/trace/skb.h   |    8 ++++++++
 net/core/Makefile     |    2 ++
 net/core/net-traces.c |   29 +++++++++++++++++++++++++++++
 3 files changed, 39 insertions(+)
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/trace/skb.h b/include/trace/skb.h
new file mode 100644
index 0000000..3aa8646
--- /dev/null
+++ b/include/trace/skb.h
@@ -0,0 +1,8 @@
+#ifndef _TRACE_SKB_H_
+#define _TRACE_SKB_H_
+
+DECLARE_TRACE(kfree_skb,
+	TPPROTO(struct sk_buff *skb, void *location),
+	TPARGS(skb, location));
+
+#endif