[CLEANUP] peers.h: fix declarations

* The declaration of peer_session_create() does
  not match its definition. As it is only
  used inside of peers.c make it static.

* Make the declaration of peers_register_table()
  match its definition.

* Also, make all functions in peers.c that
  are not also in peers.h static
diff --git a/include/proto/peers.h b/include/proto/peers.h
index d188854..349fda5 100644
--- a/include/proto/peers.h
+++ b/include/proto/peers.h
@@ -28,8 +28,7 @@
 #include <types/session.h>
 #include <types/peers.h>
 
-struct session * peer_session_create(struct peer *);
-struct session * peers_register_table(struct peers *, struct stktable *table);
+void peers_register_table(struct peers *, struct stktable *table);
 
 int peer_accept(struct session *);