[AF_RXRPC]: Add a missing goto

Add a missing goto to error handling in the RXKAD security module for
AF_RXRPC.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index e09a95a..8e69d69 100644
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -1021,6 +1021,7 @@
 
 	abort_code = RXKADINCONSISTENCY;
 	if (version != RXKAD_VERSION)
+		goto protocol_error;
 
 	abort_code = RXKADTICKETLEN;
 	if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN)