net/ipv4/tcp_fastopen.c: remove superfluous header files from tcp_fastopen.c

tcp_fastopen.c hasn't use any macro or function declared in crypto.h, err.h,
init.h, list.h, rculist.h and inetpeer.h. Thus, these files can be removed
from tcp_fastopen.c safely without affecting the compilation of the net module.

Signed-off-by: Mianhan Liu <liumh1@shanghaitech.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index 59412d6..fdbcf2a 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -1,13 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
-#include <linux/crypto.h>
-#include <linux/err.h>
-#include <linux/init.h>
 #include <linux/kernel.h>
-#include <linux/list.h>
 #include <linux/tcp.h>
 #include <linux/rcupdate.h>
-#include <linux/rculist.h>
-#include <net/inetpeer.h>
 #include <net/tcp.h>
 
 void tcp_fastopen_init_key_once(struct net *net)