tcp: Remove unreachable code in tcp_close_shutdown_fin

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Dirk Ziegelmeier <dirk@ziegelmeier.net>
(cherry picked from commit 9bbb741247cc4dc6bb748498218addbd79d82372)

src/core/tcp.c

@@ -358,7 +358,6 @@ tcp_close_shutdown_fin(struct tcp_pcb *pcb)
   default:
     /* Has already been closed, do nothing. */
     return ERR_OK;
-    break;
   }
 
   if (err == ERR_OK) {