[NET] Rename open_request to request_sock

Ok, this one just renames some stuff to have a better namespace and to
dissassociate it from TCP:

struct open_request  -> struct request_sock
tcp_openreq_alloc    -> reqsk_alloc
tcp_openreq_free     -> reqsk_free
tcp_openreq_fastfree -> __reqsk_free

With this most of the infrastructure closely resembles a struct
sock methods subset.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/ip.h b/include/linux/ip.h
index d5b7c90..31e7ced 100644
--- a/include/linux/ip.h
+++ b/include/linux/ip.h
@@ -109,7 +109,7 @@
 #define optlength(opt) (sizeof(struct ip_options) + opt->optlen)
 
 struct inet_request_sock {
-	struct open_request	req;
+	struct request_sock	req;
 	u32			loc_addr;
 	u32			rmt_addr;
 	u16			rmt_port;
@@ -123,7 +123,7 @@
 	struct ip_options	*opt;
 };
 
-static inline struct inet_request_sock *inet_rsk(const struct open_request *sk)
+static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
 {
 	return (struct inet_request_sock *)sk;
 }