SUNRPC: Clean up the RPCSEC_GSS service ticket requests

Instead of hacking specific service names into gss_encode_v1_msg, we should
just allow the caller to specify the service name explicitly.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>

include/linux/sunrpc/auth_gss.h

@@ -82,8 +82,8 @@ struct gss_cred {
 	enum rpc_gss_svc	gc_service;
 	struct gss_cl_ctx __rcu	*gc_ctx;
 	struct gss_upcall_msg	*gc_upcall;
+	const char		*gc_principal;
 	unsigned long		gc_upcall_timestamp;
-	unsigned char		gc_machine_cred : 1;
 };
 
 #endif /* __KERNEL__ */