tcp: Add missing annotation for tcp_child_process()

Sparse reports warning at tcp_child_process()
warning: context imbalance in tcp_child_process() - unexpected unlock
The root cause is the missing annotation at tcp_child_process()

Add the missing __releases(&((child)->sk_lock.slock)) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/tcp_minisocks.c

@@ -819,6 +819,7 @@ EXPORT_SYMBOL(tcp_check_req);
 
 int tcp_child_process(struct sock *parent, struct sock *child,
 		      struct sk_buff *skb)
+	__releases(&((child)->sk_lock.slock))
 {
 	int ret = 0;
 	int state = child->sk_state;