[ICSK]: Introduce reqsk_queue_prune from code in tcp_synack_timer

With this we're very close to getting all of the current TCP
refactorings in my dccp-2.6 tree merged, next changeset will export
some functions needed by the current DCCP code and then dccp-2.6.git
will be born!

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index f691058..52f5ecc 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -99,6 +99,7 @@
 #include <net/arp.h>
 #include <net/route.h>
 #include <net/ip_fib.h>
+#include <net/inet_connection_sock.h>
 #include <net/tcp.h>
 #include <net/udp.h>
 #include <linux/skbuff.h>