sunrpc: Propagate errors from xs_bind() through xs_create_sock()

xs_create_sock() is supposed to return a pointer or an ERR_PTR-encoded
error, but it currently returns 0 if xs_bind() fails.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Cc: stable@kernel.org [v2.6.37]
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/xprtsock.c

@@ -1631,7 +1631,8 @@ static struct socket *xs_create_sock(struct rpc_xprt *xprt,
 	}
 	xs_reclassify_socket(family, sock);
 
-	if (xs_bind(transport, sock)) {
+	err = xs_bind(transport, sock);
+	if (err) {
 		sock_release(sock);
 		goto out;
 	}