tcp: remove redundant new line from tcp_event_sk_skb

This removes '\n' from trace event class tcp_event_sk_skb to avoid
redundant new blank line and make output compact.

Fixes: af4325ec

 ("tcp: expose sk_state in tcp_retransmit_skb tracepoint")
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>