svcrpc: share some setup of listening sockets

There's some duplicate code here.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h
index b3f64b1..73c7a68 100644
--- a/include/linux/sunrpc/svc_xprt.h
+++ b/include/linux/sunrpc/svc_xprt.h
@@ -124,6 +124,7 @@
 			struct net *net, const sa_family_t af,
 			const unsigned short port);
 int	svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen);
+void	svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *xprt);
 
 static inline void svc_xprt_get(struct svc_xprt *xprt)
 {