CLEANUP: sock_raw: remove last references to stream_sock

We also stop exporting all functions since they're not needed anymore outside
of sock_raw.c.
diff --git a/src/session.c b/src/session.c
index 77fc32e..2cb8b66 100644
--- a/src/session.c
+++ b/src/session.c
@@ -184,7 +184,7 @@
 		s->si[0].flags = SI_FL_CAP_SPLTCP; /* TCP/TCPv6 splicing possible */
 
 	/* add the various callbacks */
-	stream_interface_prepare(&s->si[0], &stream_sock);
+	stream_interface_prepare(&s->si[0], &sock_raw);
 
 	/* pre-initialize the other side's stream interface to an INIT state. The
 	 * callbacks will be initialized before attempting to connect.