[IPV4]: Add raw drops counter.

Add raw drops counter for IPv4 in /proc/net/raw .

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/sock.c b/net/core/sock.c
index c519b43..2029d09 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1611,6 +1611,7 @@
 	sk->sk_stamp = ktime_set(-1L, -1L);
 
 	atomic_set(&sk->sk_refcnt, 1);
+	atomic_set(&sk->sk_drops, 0);
 }
 
 void fastcall lock_sock_nested(struct sock *sk, int subclass)