[PATCH net] net: add inline annotation to fix the build warning

[Moon Yeounsu <yyyynoom@gmail.com>]

This patch fixes two sparse warnings (`make C=1`):
net/ipv6/icmp.c:103:20: warning: context imbalance in 'icmpv6_xmit_lock' - wrong count at exit
net/ipv6/icmp.c:119:13: warning: context imbalance in 'icmpv6_xmit_unlock' - unexpected unlock

Since `icmp6_xmit_lock()` and `icmp6_xmit_unlock()` are designed as they
are named, entering/returning the function without lock/unlock doesn't
matter.

Signed-off-by: Moon Yeounsu <yyyynoom@gmail.com>
---
 net/ipv6/icmp.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 071b0bc1179d..d8cc3d63c942 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -101,6 +101,7 @@ static const struct inet6_protocol icmpv6_protocol = {
 
 /* Called with BH disabled */
 static struct sock *icmpv6_xmit_lock(struct net *net)
+	__acquires(&sk->sk_lock.slock)
 {
 	struct sock *sk;
 
@@ -117,6 +118,7 @@ static struct sock *icmpv6_xmit_lock(struct net *net)
 }
 
 static void icmpv6_xmit_unlock(struct sock *sk)
+	__releases(&sk->sk_lock.slock)
 {
 	sock_net_set(sk, &init_net);
 	spin_unlock(&sk->sk_lock.slock);
-- 
2.46.1