[IPV6]: ICMP6_MIB_OUTMSGS increment duplicated

icmpv6_send() calls ip6_push_pending_frames() indirectly.
Both ip6_push_pending_frames() and icmpv6_send() increment
counter ICMP6_MIB_OUTMSGS.

This patch remove the increment from icmpv6_send.
Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/icmp.c

@@ -458,8 +458,6 @@ void icmpv6_send(struct sk_buff *skb, int type, int code, __u32 info,
 	}
 	err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, len + sizeof(struct icmp6hdr));
 
-	ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTMSGS);
-
 out_put:
 	if (likely(idev != NULL))
 		in6_dev_put(idev);